Method for preventing or reducing low speed pre-ignition in direct injection spark ignition engine with molybdenum-containing lubricant composition

Abstract

A lubricant composition for a direct injection, pressurized, spark-ignited internal combustion engine is disclosed that includes one or more molybdenum-containing compounds and one or more calcium detergents. The present disclosure also relates to a method for reducing or preventing low speed pre-ignition (LSPI) during at least one oil change interval.

Description

[0001] Related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 378,599, filed on October 6, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a lubricant composition for a direct injection, supercharged, spark-ignited internal combustion engine containing a molybdenum-containing compound and a calcium detergent. The present disclosure also relates to a method for preventing or reducing low-speed pre-ignition in an engine lubricated with a formulated oil. Background Art

[0004] Modern engine designs are constantly evolving to improve fuel economy without sacrificing performance or durability. Historically, gasoline was port fuel injected (PFI), meaning it was injected through the intake ports and passed through the intake valves into the combustion chamber. Gasoline direct injection (GDI) involves injecting gasoline directly into the combustion chamber.

[0005] Under certain circumstances, an internal combustion engine may experience abnormal combustion. Abnormal combustion in a spark-ignited internal combustion engine can be understood as an uncontrolled explosion in the combustion chamber caused by ignition of combustible elements in the combustion chamber by a source other than the igniter.

[0006] Pre-ignition can be understood as an abnormal form of combustion caused by the air-fuel mixture igniting before the igniter is ignited. Any time the air-fuel mixture in the combustion chamber ignites before being ignited by the igniter, it can be understood as pre-ignition.

[0007] Without being bound by a particular theory, pre-ignition traditionally occurs during high engine speeds when a specific point within the cylinder combustion chamber may become hot enough during high engine speeds to effectively act as a glow plug (e.g., an overheated spark plug tip, an overheated metal burr), providing an ignition source that causes the air-fuel mixture to ignite before being ignited by the igniter. This pre-ignition may be more commonly referred to as hot spot pre-ignition and can be suppressed by simply locating the hot spot and eliminating it.

[0008] Recently, automakers have observed intermittent abnormal combustion in production turbocharged gasoline engines, particularly at low speeds and moderate to high loads. More specifically, when operating the engine at speeds of 3,000 rpm or less and under loads with a brake mean effective pressure (BMEP) greater than or equal to 10 bar, a condition known as low-speed pre-ignition (LSPI) can occur in a random and haphazard manner. Furthermore, the propensity for LSPI to occur is related to engine oil formulation, with the number of LSPI events increasing with engine oil aging.

[0009] While some engine knock and pre-ignition problems can and are being addressed through the use of new engine technologies, such as electronic controls and knock sensors, and through optimization of engine operating conditions, there remains a need for lubricant compositions that can reduce or prevent the problems.

[0010] The presently disclosed engine oil lubricant is suitable for reducing, inhibiting, or even eliminating LSPI events in direct injection engines by operating the engine with a lubricant containing a molybdenum compound. Typical engine oils designed to reduce LSPI events perform well initially, but their performance declines dramatically over time. In stark contrast, the disclosed engine oil lubricant is specifically designed to maintain its LSPI-reducing capability throughout its normal service life. Summary of the Invention

[0011] Thus, in one aspect, the present disclosure provides a method for preventing or reducing low-speed pre-ignition in a direct-injection, supercharged, spark-ignition internal combustion engine, the method comprising the steps of lubricating the engine with a used or aged lubricant composition comprising:

[0012] (i) one or more oils of lubricating viscosity;

[0013] (ii) one or more molybdenum-containing compounds in an amount to provide the lubricant composition with at least about 100 ppm of molybdenum based on the total weight of the composition; and

[0014] (iii) one or more calcium detergents in an amount to provide the lubricant composition with at least about 1000 ppm calcium based on the total weight of the composition;

[0015] wherein the used or aged lubricant composition lubricates the engine during at least one oil change interval.

[0016] For example, the molybdenum-containing compound is an oil-soluble or oil-dispersible molybdenum compound, including molybdenum-amine complexes, molybdenum dithiocarbamates, molybdenum dithiophosphates, and the like, and combinations thereof.

[0017] In certain embodiments, the amount of the one or more molybdenum-containing compounds provides the lubricant composition with at least about 850 ppm of molybdenum, based on the total weight of the composition; and the amount of the one or more calcium detergents provides the lubricant composition with at least about 1800 ppm of calcium, based on the total weight of the composition.

[0018] In other embodiments, the amount of the one or more molybdenum-containing compounds provides the lubricant composition with about 100 ppm to about 850 ppm of molybdenum, based on the total weight of the composition; and the amount of the one or more calcium detergents provides the lubricant composition with about 1000 to about 1450 ppm of calcium, based on the total weight of the composition. DETAILED DESCRIPTION

[0019] definition

[0020] In order to more clearly define the terms used herein, the following definitions are provided. Unless otherwise indicated, the following definitions apply to the present disclosure. If a term is used in the present disclosure, but is not specifically defined herein, the definition from IUPAC Compendium of Chemical Terminology can be applied, provided that the definition does not conflict with any other disclosure or definition used herein, or does not make any claim applying the definition become unclear or infeasible. If any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided herein, it should be understood that the definition or usage provided herein shall prevail.

[0021] In this disclosure, although compositions and methods or processes are often described as “comprising” various components or steps, unless otherwise stated, the compositions and methods can also “consist essentially of” or “consist of” the various components or steps.

[0022] The terms "a," "an," and "the" are intended to include plural alternatives, such as at least one. The terms "including" and / or "with" and "having" as used herein are defined as comprising (i.e., open ended) unless otherwise specified.

[0023] Various numerical ranges are disclosed herein. When applicants disclose or claim any type of range, applicants intend to disclose or claim individually every possible number that the range could reasonably encompass, including the endpoints of the range and any subranges and combinations of subranges encompassed therein, unless otherwise specified. For example, all numerical endpoints of ranges disclosed herein are approximate unless otherwise specified.

[0024] "Major amount" means greater than 50% by weight of the composition.

[0025] "Minor amount" means less than 50% by weight of the composition.

[0026] When used in conjunction with metal detergents, the term "overbased" is used to indicate that the metal salt is present in a stoichiometric amount greater than the amount of organic groups.

[0027] As referred to herein, the term "ppm" means parts per million by weight based on the total weight of the lubricant composition.

[0028] The "metal content" of a lubricant composition or detergent component, such as the magnesium content, calcium content, or total metal content (ie, the sum of all individual metal contents), is measured by ASTM D4951.

[0029] With respect to a lubricant composition, the term "used" or "aged" means that the lubricant is not fresh. A used or aged lubricant composition generally exhibits levels of oxidation, nitration, neutralization, fuel dilution, soot, and / or wear corresponding to the aging of the composition under actual use conditions. In certain embodiments, the used lubricant composition has been used during at least one oil change interval or on a vehicle traveling a distance of at least about 3,000 miles, 4,000 miles, 5,000 miles, 6,000 miles, 7,000 miles, or 8,000 miles. In certain embodiments, the used lubricant composition is used after the vehicle has traveled a distance of about 3000 to about 20,000 miles, about 4000 to about 20,000 miles, about 5000 to about 20,000 miles, about 6000 to about 20,000 miles, about 7000 to about 20,000 miles, about 8000 to about 20,000 miles, about 3000 to about 15,000 miles, about 4000 to about 15,000 miles, about 5000 to about 20,000 miles, about 6000 to about 20,000 miles, about 7000 to about 20,000 miles, about 8000 to about 20,000 miles, about 8000 to about 20,000 miles, about 9000 to about 15,000 miles, about 10000 to about 15,000 miles, about 15 ... and about 15,000 miles, about 6000 to about 15,000 miles, about 7000 to about 15,000 miles, about 8000 to about 15,000 miles, about 3000 to about 10,000 miles, about 4000 to about 10,000 miles, about 5000 to about 10,000 miles, about 6000 to about 10,000 miles, about 7000 to about 10,000 miles, or about 8000 to about 10,000 miles.

[0030] In some embodiments, the used or aged lubricant composition has been used or aged for at least 1,000 miles, such as at least 2,000 miles, at least 3,000 miles, at least 4,000 miles, at least 5,000 miles, at least 6,000 miles, at least 7,000 miles, at least 8,000 miles, at least 9,000 miles, or at least 10,000 miles.

[0031] In certain embodiments, the used or aged characteristics of a lubricant composition can be simulated for testing purposes, i.e., the lubricant composition can be artificially aged by simulating the conditions of use in an engine. For example, an artificially aged lubricant composition for testing can be produced by iron-catalyzed oxidation at a temperature in the range of about 150° C. to 170° C. for a period of about 110 to 150 hours according to the GFC Lu-43A-11 method. In certain embodiments, the used or aged characteristics of a lubricant composition can be simulated, for example, as described in Example 6, to provide a lubricant composition that is comparable to a lubricant composition used under normal driving conditions for a desired distance (e.g., 5,000 miles).

[0032] The term "boost" is used throughout this specification. Boosting refers to running an engine at a higher intake pressure than a naturally aspirated engine can achieve. Boosting can be achieved through the use of a turbocharger (driven by the exhaust) or a supercharger (driven by the engine). Providing higher power density with a smaller engine allows engine manufacturers to provide superior performance while reducing friction and pumping losses. This is achieved by increasing boost pressure using a turbocharger or mechanical supercharger and reducing the engine speed through the use of a higher transmission gear ratio permitted by the production of higher torque at lower engine speeds. However, higher torque at lower engine speeds has been found to result in LSPI events, resulting in extremely high peak cylinder pressures, which can lead to catastrophic engine failure. The possibility of LSPI has prevented engine manufacturers from fully optimizing engine torque at lower engine speeds in such smaller, high-output engines.

[0033] The term "oil-soluble" or "oil-dispersible" means that the amount required to provide the desired level of activity or performance can be incorporated by dissolving, dispersing, or suspending in an oil of lubricating viscosity. Typically, this means that at least about 0.001% by weight of the material can be incorporated into the lubricant composition. For further discussion of the terms oil-soluble and oil-dispersible, particularly "stable dispersion," see U.S. Patent No. 4,320,019, which is expressly incorporated herein by reference for its relevant teachings in this regard.

[0034] As used herein, the term "sulfated ash" refers to the incombustible residue resulting from detergents and metal additives in a lubricant.Sulfated ash can be determined using ASTM test D874.

[0035] As used herein, the term "total base number" or "TBN" refers to the amount of base equivalent to milligrams of KOH in one gram of sample. Thus, a higher TBN value reflects more basic products and, therefore, higher basicity. TBN is determined using the ASTM D 2896 test.

[0036] Unless otherwise indicated, all percentages are by weight.

[0037] Unless otherwise specified, the term "alkyl" as used herein includes C1 to C 24 The term "alkyl" refers to a saturated straight-chain hydrocarbon, branched-chain hydrocarbon, cyclic hydrocarbon, primary hydrocarbon, secondary hydrocarbon or tertiary hydrocarbon. The term includes both substituted and unsubstituted alkyl groups. The portion of the alkyl group that can be substituted is selected from the group consisting of hydroxyl, halo (F, Cl, Br, I), amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate or phosphonate, which can be unprotected or protected as needed, as known to those skilled in the art, for example, as taught by Greene et al., Protective Groups in Organic Synthesis, John Wiley and Sons, Second Edition, 1991, incorporated herein by reference. When referring to an alkyl group being substituted by an alkyl group, this is used interchangeably with "branched alkyl group". Specific examples of alkyl and / or substituted alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, stearyl, eicosyl, docosyl, tetracosyl, triacontyl, 2-ethylhexyl, 2-butyloctyl, 2-butyldecyl, 2-hexyloctyl, 2-hexyldecyl, 2-octyldecyl, 2-hexyldodecyl, 2-octyldodecyl, 2-decyltetradecyl, 2-dodecylhexadecyl, 2-hexadecyloctadecyl, 2-tetradecyloctadecyl, myristoyl, palmitoyl, and stearoyl.

[0038] The term "cycloalkyl" or "cyclic alkyl" refers to an alkyl species containing 3 to 15 carbon atoms, including one or more rings, and without alternating or resonant double bonds between carbon atoms. The term includes both substituted and unsubstituted cycloalkyl groups. The portion of the cycloalkyl group that can be substituted is selected from the group consisting of hydroxyl, halo (F, Cl, Br, I), amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate or phosphonate, which can be unprotected or protected as needed, as known to those skilled in the art, for example, as taught by Greene et al., Protective Groups in Organic Synthesis, John Wiley and Sons, Second Edition, 1991, incorporated herein by reference. For example, cycloalkyl includes but is not limited to cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. In certain embodiments, cycloalkyl contains 1 to 4 rings that can be fused. In certain embodiments, cycloalkyl groups can contain one or more double bonds or triple bonds in one or more rings.

[0039] The term "alkenyl" includes straight chain, branched chain or cyclic hydrocarbon groups containing 2 to 10 carbon atoms and at least one carbon-carbon double bond. Examples of alkenyl groups include ethenyl, propenyl, butenyl and cyclohexenyl.

[0040] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, typical methods and materials are described herein.

[0041] All publications and patents mentioned herein are incorporated herein by reference to describe and disclose, for example, the constructions and methods described in the publications, which may be used in conjunction with the presently described invention. The publications discussed in full are provided solely for their disclosure prior to the filing date of the present application. Nothing herein shall be construed as an admission that the inventors have unauthorized reliance on prior invention to antedate this disclosure.

[0042] Lubricant compositions and methods

[0043] The present disclosure generally relates to methods for reducing or preventing low-speed pre-ignition (LSPI) in a direct-injection, supercharged, spark-ignition internal combustion engine during or between oil drain intervals. In another aspect, the present disclosure provides methods for maintaining the low-speed pre-ignition reduction capability of a used or aged lubricant composition in a direct-injection, supercharged, spark-ignition internal combustion engine. The lubricant composition used in the methods according to the present disclosure comprises: (i) one or more oils of lubricating viscosity; (ii) one or more molybdenum-containing compounds; and (iii) one or more calcium detergents. Exemplary lubricant compositions are suitable for reducing, preventing, inhibiting, or eliminating LSPI events in a direct-injection, supercharged, spark-ignition internal combustion engine containing a used or aged lubricant composition.

[0044] Lubricant compositions provide LSPI reduction when fresh or immediately applied to an engine crankcase, but can experience degradation of such properties after use or aging. Used or aged lubricant compositions can exacerbate pre-ignition. Applicants have discovered that lubricant compositions according to embodiments maintain their LSPI reduction capabilities during use or aging (i.e., over the long term). By using methods according to the present invention, exemplary lubricant compositions can be used to prevent or reduce LSPI in direct-injection, supercharged, spark-ignition internal combustion engines for an extended period of use without significant loss of performance. Using lubricant compositions according to the present invention in place of comparative lubricant compositions can reduce the need to replace lubricant compositions in an engine to reduce LSPI.

[0045] Low-speed pre-ignition is most likely to occur in a direct-injection, supercharged (turbocharged or supercharged), spark-ignited (gasoline) internal combustion engine that, when operating, produces a brake mean effective pressure (BMEP) level of at least about 15 bar (peak torque), at least about 18 bar, or at least about 20 bar at an engine speed of about 1500 to about 2500 revolutions per minute (rpm), or about 1500 to about 2000 rpm. As used herein, "brake mean effective pressure" or "BMEP" is defined as the work performed during one engine cycle divided by the engine swept volume; engine torque normalized by engine displacement. The term "brake" refers to the actual torque / power available at the engine flywheel as measured on a dynamometer. Thus, BMEP is a measure of the useful power output of an engine.

[0046] In one embodiment, the engine is operated at a speed of 500 rpm to 3000 rpm, or 800 rpm to 2800 rpm, or about 1000 rpm to 2600 rpm. In addition, the engine can be operated at a brake mean effective pressure of 10 bar to about 30 bar, about 12 bar to about 30 bar, or about 12 bar to about 24 bar.

[0047] LSPI events, while relatively uncommon, can be catastrophic in nature. Therefore, it is desirable to substantially reduce or even eliminate LSPI events during normal or ongoing operation of a direct fuel injection engine.

[0048] In one embodiment, the methods of the present invention reduce the number of LSPI events by at least 10%, at least 20%, at least 30%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to an oil or lubricant composition without the one or more molybdenum compounds and one or more calcium detergents according to the embodiments.

[0049] Thus, in one aspect, the present disclosure provides a method for preventing or reducing LSPI in a direct injection, supercharged, spark-ignition internal combustion engine, the method comprising the step of lubricating the engine with a used or aged lubricant composition comprising:

[0050] (i) one or more oils of lubricating viscosity;

[0051] (ii) one or more molybdenum-containing compounds in an amount to provide the lubricant composition with at least about 100 ppm of molybdenum based on the total weight of the composition; and

[0052] (iii) one or more calcium detergents in an amount to provide the lubricant composition with at least about 1000 ppm calcium based on the total weight of the composition;

[0053] wherein the used or aged lubricant composition lubricates the engine during at least one oil change interval.

[0054] In one embodiment, (ii) the amount of the one or more molybdenum-containing compounds provides the lubricant composition with at least about 850 ppm of molybdenum, based on the total weight of the composition; and (iii) the amount of the one or more calcium detergents provides the lubricant composition with at least about 1800 ppm of calcium, based on the total weight of the composition.

[0055] In another embodiment, (ii) the amount of the one or more molybdenum-containing compounds provides the lubricant composition with about 100 ppm to about 850 ppm of molybdenum, based on the total weight of the composition; and (iii) the amount of the one or more calcium detergents provides the lubricant composition with about 1000 to about 1450 ppm of calcium, based on the total weight of the composition.

[0056] In certain embodiments, (iii) the amount of one or more calcium detergents provides the lubricant composition with less than about 3500 ppm, less than about 3000 ppm, less than about 2500 ppm, less than about 2400 ppm, less than about 2300 ppm, less than about 2200 ppm, less than about 2100 ppm, less than about 2000 ppm, less than about 1900 ppm, less than about 1800 ppm, less than about 1700 ppm, less than about 1600 ppm, less than about 1500 ppm, or less than about 1450 ppm of calcium, based on the total weight of the composition.

[0057] In certain embodiments, the direct injection, supercharged, spark ignition internal combustion engine is a downsized engine or an engine ranging in size from about 0.5 liters to about 3.6 liters.

[0058] In certain embodiments, the engine is a downsized turbocharged engine.

[0059] Certain embodiments provide a method for maintaining the LSPI reducing capability of a used or aged lubricant composition in a direct injection, supercharged, spark-ignition internal combustion engine, wherein the method comprises the step of lubricating the engine with a lubricant composition described herein.

[0060] In one embodiment, the present disclosure provides a lubricating engine oil composition comprising a lubricant base stock (generally referred to as "base oil") as a major component and an LSPI additive as disclosed herein (e.g., one or more molybdenum compounds and one or more calcium detergents) as a minor component; and wherein the engine exhibits greater than a 50% reduction in LSPI based on normalized LSPI counts per 100,000 engine cycles, the engine operating at 500 to 3,000 rpm, and a BMEP of 10 to 30 bar, as compared to the LSPI performance achieved in an engine using a lubricant that does not contain the LSPI additive, wherein the LSPI additive comprises one or more molybdenum-containing compounds according to embodiments disclosed herein and one or more calcium detergents.

[0061] In one aspect, the present disclosure provides a lubricating engine oil composition for a downsized, supercharged engine comprising a lubricant base stock as a major component and an LSPI additive as disclosed herein as a minor component; wherein the downsized engine has a range of about 0.5 to about 3.6 liters, about 0.5 to about 3.0 liters, about 0.8 to about 3.0 liters, about 0.5 to about 2.0 liters, or about 1.0 to about 2.0 liters. The engine may have two, three, four, five, or six cylinders.

[0062] In one aspect, the present disclosure provides the use of a lubricant composition as disclosed herein for preventing or reducing LSPI in a direct-injection, supercharged, spark-ignition internal combustion engine, particularly LSPI in an aged or used lubricating engine oil composition.

[0063] The methods disclosed herein can be used to prevent or reduce LSPI events in direct injection, supercharged, spark-ignition internal combustion engines, particularly in aged or used lubricant compositions.

[0064] LSPI events are determined by monitoring the peak cylinder pressure (PP) and mass fraction burned (MFB) of the in-cylinder fuel charge. PP is typically reported in bar, while MFB is typically reported in crankshaft degrees. An LSPI event is said to have occurred when one or both of these criteria are met (i.e., the PP and / or MFB thresholds are met and / or exceeded). The peak cylinder pressure threshold varies from test to test, but is typically 4-5 standard deviations above the mean cylinder pressure. Similarly, the MFB threshold is typically 4-5 standard deviations earlier than the mean MFB. LSPI events can be reported as an average of events per test, events per 100,000 combustion cycles, events per cycle, and / or combustion cycles per event. In one embodiment, the number of LSPI events is the number of combustion events in which MFB02 (2% of MFB) exceeds ~4.7 standard deviations and the peak pressure (PP) exceeds 90 bar pressure (e.g., 95 bar pressure, 100 bar pressure, 105 bar pressure, 110 bar pressure, 115 bar pressure, 120 bar pressure, etc.). In some embodiments, the number of LSPI events is less than 5 events, less than 4 events, less than 3 events, less than 2 events, or less than 1 event. In one embodiment, the number of LSPI events is zero events, or LSPI events are completely suppressed.

[0065] It has now been discovered that by lubricating LSPI-prone engines with the lubricant compositions disclosed herein, the occurrence of LSPI in such engines can be reduced, and more specifically, that this reduction in LSPI events persists as the lubricant composition ages.

[0066] The present disclosure further provides the methods described herein, wherein the engine is fueled by a liquid hydrocarbon fuel, a liquid non-hydrocarbon fuel, or a mixture thereof.

[0067] The present disclosure further provides the method described herein, wherein the engine is fueled by natural gas, liquefied petroleum gas (LPG), compressed natural gas (CNG), or a mixture thereof.

[0068] The lubricant compositions of the present invention comprise: (i) one or more oils of lubricating viscosity; (ii) one or more molybdenum-containing compounds in an amount to provide the lubricant composition with at least about 100 ppm of molybdenum, based on the total weight of the composition; and (iii) one or more calcium detergents in an amount to provide the lubricant composition with at least about 1000 ppm of calcium, based on the total weight of the composition.

[0069] Typically, the lubricant composition is used in conjunction with a lubricating engine oil composition.One or more oils of lubricating viscosity constitute the major component of the lubricant composition.

[0070] Molybdenum compounds

[0071] The lubricant composition according to the embodiment comprises one or more molybdenum-containing compounds. The molybdenum-containing compound can be any oil-soluble or oil-dispersible molybdenum-containing compound. The molybdenum compound can be mononuclear, dinuclear or trinuclear.

[0072] Examples of oil-soluble or oil-dispersible organic molybdenum compounds include molybdenum amine complexes, molybdenum dithiocarbamates, molybdenum dithiophosphates, molybdenum dithiophosphinates, molybdenum xanthates, molybdenum thioxanthates, molybdenum carboxylates, molybdenum alkoxides, organic molybdenum complexes, dispersed hydrated molybdenum compounds, and the like, and combinations thereof.

[0073] In one embodiment, the one or more molybdenum-containing compounds include or consist of a molybdenum-amine complex, a molybdenum dithiocarbamate, and a molybdenum dithiophosphate. In one embodiment, the one or more molybdenum-containing compounds include or consist of a molybdenum-amine complex and a molybdenum dithiophosphate.

[0074] In one embodiment, the molybdenum-containing compound is sulfurized oxymolybdenum dithiocarbamate, sulfurized oxymolybdenum dithiophosphate, an amine-molybdenum complex compound, oxymolybdenum diethylate amide, and oxymolybdenum monoglyceride.

[0075] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum-amine complex. In one embodiment, the molybdenum-amine complex is a molybdenum-succinimide complex. In one embodiment, the one or more molybdenum-containing compounds include an oxymolybdenum complex of succinimide, particularly an oxymolybdenum complex of a sulfur-containing succinimide.

[0076] The molybdenum-amine complex can be generally characterized as a molybdenum or molybdenum / sulfur complex containing a basic nitrogen compound. The molybdenum compound used to prepare the molybdenum-amine complex is a basic molybdenum compound (such as including molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate and other alkali metal molybdates and other molybdenum salts, such as MoOCl4, MoO2Br2, Mo2O3Cl6, molybdenum trioxide or similar acidic molybdenum compounds). The basic nitrogen compound must have a basic nitrogen content as measured by ASTM D-664 or D-2896. Typical such compositions are succinimide, carboxylic acid amide, hydrocarbon monoamine, hydrocarbon polyamine, Mannich bases, phosphamide, (thio)phosphamide and combinations thereof. Examples of succinimide include succinimide with an alkyl or alkenyl group having 8 or more carbon atoms (such as 8 to 400 carbon atoms). In certain embodiments, succinimide has an alkyl or alkenyl group having 8 to 30, 12 to 30 or 8 to 18 carbon atoms.

[0077] The molybdenum / nitrogen complexes employed herein are well known in the art and are complexes of molybdic acid and an oil-soluble basic nitrogen-containing compound. Typically, the molybdenum / nitrogen complexes can be prepared using an organic solvent containing a polar promoter during the complexation step, and procedures for preparing such complexes are described, for example, in U.S. Patent Nos. 4,259,194; 4,259,195; 4,261,843; 4,263,152; 4,265,773; 4,283,295; 4,285,822; 4,369,119; 4,370,246; 4,394,279; 4,402 No. 6,962,896; No. 8,022,022; No. 8,022,023; No. 8,076,275; No. 8,183,189; No. 8,193,131; No. 8,193,132; No. 8,426,608; No. 8,476,460; and No. 8,980,806; and U.S. Patent Application Publication Nos. 2013 / 0261313; 2014 / 0179573; and 2014 / 0018269. As shown in these references, the molybdenum / nitrogen-containing complex can be further sulfurized.

[0078] For example, mono- and polysuccinimides useful in preparing the molybdenum-complexes described herein are disclosed in numerous references and are well known in the art. Certain basic types of succinimides and related materials encompassed by the art term "succinimide" are taught in U.S. Patent Nos. 3,219,666; 3,172,892; and 3,272,746, the disclosures of which are incorporated herein by reference. The term "succinimide" is understood in the art to include a variety of amide, imide, and amidine species that may also be formed. However, the primary product is succinimide, and this term has been generally accepted to mean the product of the reaction of an alkenyl-substituted succinic acid or anhydride with a nitrogen-containing compound. Due to their commercial availability, preferred succinimides are those prepared from hydrocarbyl succinic anhydrides and ethyleneamines, wherein the hydrocarbyl group contains from about 24 to about 350 carbon atoms, particularly ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine. Particularly preferred are those prepared from polyisobutenyl succinic anhydrides having from 70 to 128 carbon atoms and tetraethylenepentamine or triethylenetetramine, or mixtures thereof. The term "succinimide" also includes co-oligomers of hydrocarbyl succinic acids or anhydrides and polysecondary amines containing at least one tertiary amino nitrogen in addition to two or more secondary amino groups. Typically, such compositions have an average molecular weight of 1,500 to 50,000. Typical compounds are those prepared by reacting polyisobutenyl succinic anhydride with ethylene dipiperazine.

[0079] Succinimides having an average molecular weight of 1000, 1300 or 2300 and mixtures thereof are most preferred.

[0080] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum dithiophosphate (eg, a molybdenum dialkyl dithiophosphate).

[0081] A type of molybdenum dithiocarbamate used herein is represented by the following formula (1):

[0082]

[0083] where R 1 and R 2 Independently selected from C4-C 30 alkyl group and x is an integer from 0 to 4. Each R 1 and R 2 Examples of commercially available molybdenum dialkyl dithiophosphates include those available from RT Vanderbilt Company. L (molybdenum di-(2-ethylhexyl) dithiophosphate) or Sakara-lube available from Adeka or Sakura-lube product.

[0084] In certain embodiments, R 1 and R 2 Independently selected from C4-C 24 In certain embodiments, R 1 and R 2 Independently selected from C6-C 18 Alkyl group.

[0085] In certain embodiments, x is 0. In certain embodiments, x is 1. In certain embodiments, x is 2. In certain embodiments, x is 3. In certain embodiments, x is 4.

[0086] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum dithiocarbamate (eg, a molybdenum dialkyldithiocarbamate).

[0087] A type of molybdenum dithiocarbamate used herein (e.g., dimer molybdenum dithiocarbamate) is represented by the following formula (2):

[0088]

[0089] where R 3 and R 4 Independently selected from C4-C 30 alkyl group and x is an integer from 0 to 4. Each R 3 and R 4 The dimers may be symmetrical or asymmetrical. Examples of commercially available molybdenum dialkyldithiocarbamates include those available from RT Van der Bilt. 807, 822 and 2000.

[0090] In certain embodiments, R 3 and R 4 Independently selected from C4-C 24 In certain embodiments, R 3 and R 4 Independently selected from C6-C 18 Alkyl group.

[0091] In certain embodiments, x is 0. In certain embodiments, x is 1. In certain embodiments, x is 2. In certain embodiments, x is 3. In certain embodiments, x is 4.

[0092] Another type of molybdenum dithiocarbamate used herein (e.g., trimer molybdenum dithiocarbamate) is represented by the following formula (3):

[0093] Mo3S y L n

[0094] Formula (3)

[0095] wherein y is an integer from 4 to 10; n is an integer from 1 to 4; and each L is an alkyl dithiocarbamate group, wherein each alkyl group is selected from C4-C 30 Alkyl group.

[0096] In one embodiment, y is 4. In one embodiment, y is 5. In one embodiment, y is 6. In one embodiment, y is 7. In one embodiment, y is 8. In one embodiment, y is 9. In one embodiment, y is 10.

[0097] In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4.

[0098] In certain embodiments, each L is an alkyl dithiocarbamate group, wherein each alkyl group is selected from C4-C 24 In certain embodiments, each L is an alkyl dithiocarbamate group, wherein each alkyl group is selected from C6-C 18 Alkyl group.

[0099] In certain embodiments, the molybdenum-containing compound is not a molybdenum dithiocarbamate.

[0100] In one embodiment, the one or more molybdenum-containing compounds include molybdenum dithiophosphinate.

[0101] In one embodiment, the one or more molybdenum-containing compounds include molybdenum xanthate, for example a molybdenum-alkyl xanthate, such as molybdenum-ethyl xanthate.

[0102] In one embodiment, the one or more molybdenum-containing compounds include molybdenum thioxanthate.

[0103] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum carboxylate.

[0104] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum alkoxide.

[0105] In one embodiment, the one or more molybdenum-containing compounds include an organo-amine complex.

[0106] The two types of organo-molybdenum complexes used herein are represented by the following formula (4a) and formula (4b):

[0107]

[0108] where R 5 and R 6 Independently selected from C4-C 30 alkyl group, and X 1 and X 2 Each independently represents O or NH. 5 and R 6 Can be the same or different. X 1 and X 2 Can be the same or different.

[0109] In certain embodiments, R 5 and R 6 Independently selected from C4-C 24 In certain embodiments, R 5 and R 6 Independently selected from C6-C 18 Alkyl group.

[0110] In certain embodiments, X 1 Is O. In certain embodiments, X 1 In certain embodiments, X 2 Is O. In certain embodiments, X 2 For NH.

[0111] Another type of organic molybdenum complex used herein is represented by the following formula (5):

[0112] Mo3S y L n Q p

[0113] Formula (5)

[0114] wherein y is an integer from 4 to 7; n is an integer from 1 to 4; and each L is an independently selected ligand having an organic group having a sufficient number of carbon atoms to render the compound soluble or dispersible in oil; and Q is selected from the group of neutral electron-donating compounds such as water, amines, alcohols, phosphines, and ethers; and p is an integer from 0 to 5.

[0115] In one embodiment, y is 4. In one embodiment, y is 5. In one embodiment, y is 6. In one embodiment, y is 7.

[0116] In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4.

[0117] In certain embodiments, each L comprises at least 5 carbon atoms. In certain embodiments, the total number of carbon atoms comprised in all L groups is at least 21, at least 25, at least 30, or at least 35.

[0118] In certain embodiments, Q is selected from the group consisting of water, hydroxide, alcoholate, oxo, phosphine, phosphite, ammonia, amino, amido, halide, and combinations thereof.

[0119] In certain embodiments, p is 0. In certain embodiments, p is 1. In certain embodiments, p is 2. In certain embodiments, p is 3. In certain embodiments, p is 4.

[0120] In one embodiment, the one or more molybdenum-containing compounds include dispersible hydrated molybdenum compounds. Examples of dispersible hydrated molybdenum compounds include dispersible hydrated polymolybdates, dispersible hydrated alkali metal polymolybdates, and the like, and combinations thereof. Suitable dispersible hydrated polymolybdates include, for example, those disclosed in U.S. Patent No. 7,884,058.

[0121] In general, the amount of platinum in the lubricant composition increases with the amount of calcium. In certain embodiments, the amount of one or more molybdenum-containing compounds is such as to provide the lubricant composition with at least 100 ppm, at least 150 ppm, at least 166 ppm, at least 200 ppm, at least 250 ppm, at least 270 ppm, at least 300 ppm, at least 350 ppm, at least 400 ppm, at least 450 ppm, at least 500 ppm, at least 550 ppm, at least 600 ppm, at least 650 ppm, at least 700 ppm, at least 750 ppm, at least 800 ppm, at least 850 ppm, at least 900 ppm, at least 950 ppm, at least 1000 ppm, at least 1100 ppm, at least 1200 ppm, or at least 1300 ppm of platinum, based on the total weight of the composition.

[0122] In one embodiment, the amount of metal from the molybdenum-containing compound in the lubricant composition does not exceed about 2000 ppm.

[0123] In certain embodiments, the amount of the one or more molybdenum-containing compounds is such as to provide the lubricant composition with about 100 ppm to about 2000 ppm, about 150 ppm to about 2000 ppm, about 166 ppm to about 2000 ppm, about 200 ppm to about 2000 ppm, about 250 ppm to about 2000 ppm, about 270 ppm to about 2000 ppm, about 300 ppm to about 2000 ppm, about 350 ppm to about 2000 ppm, about 400 ppm to about 2000 ppm, about 450 ppm to about 2000 ppm, about 50 ... about 550 ppm to about 2000 ppm, about 600 ppm to about 2000 ppm, about 650 ppm to about 2000 ppm, about 700 ppm to about 2000 ppm, about 750 ppm to about 2000 ppm, about 800 ppm to about 2000 ppm, about 850 ppm to about 2000 ppm, about 900 ppm to about 2000 ppm, about 950 ppm to about 2000 ppm, about 1000 ppm to about 2000 ppm, about 1100 ppm to about 2000 ppm, about 1200 ppm to about 2000 ppm, or about 1300 ppm to about 2000 ppm of platinum.

[0124] In certain embodiments, the amount of the one or more molybdenum-containing compounds is to provide the lubricant composition with about 100 ppm to about 1200 ppm, about 150 ppm to about 1200 ppm, about 200 ppm to about 1200 ppm, about 250 ppm to about 1200 ppm, about 270 ppm to about 1200 ppm, about 300 ppm to about 1200 ppm, about 350 ppm to about 1200 ppm, about 400 ppm to about 1200 ppm, about 450 ppm to about 1200 ppm, about 500 ppm to about 1200 ppm, about 550 ppm to about 1200 ppm, about 600 ppm to about 1200 ppm, about 650 ppm to about 1200 ppm, about 700 ppm to about 1200 ppm, about 750 ppm to about 1200 ppm, about 800 ppm to about 1200 ppm, about 850 ppm to about 1200 ppm, or about 900 ppm to about 1200 ppm of molybdenum, based on the total weight of the composition.

[0125] In certain embodiments, the amount of the one or more molybdenum-containing compounds is to provide the lubricant composition with about 100 ppm to about 850 ppm, about 150 ppm to about 850 ppm, about 200 ppm to about 850 ppm, about 250 ppm to about 850 ppm, about 270 ppm to about 850 ppm, about 300 ppm to about 850 ppm, about 350 ppm to about 850 ppm, about 400 ppm to about 850 ppm, about 450 ppm to about 850 ppm, about 500 ppm to about 850 ppm, about 550 ppm to about 850 ppm, about 600 ppm to about 850 ppm, about 650 ppm to about 850 ppm, or about 700 ppm to about 850 ppm of platinum, based on the total weight of the composition.

[0126] In certain embodiments, the amount of the one or more molybdenum-containing compounds is to provide the lubricant composition with about 100 ppm to about 800 ppm, about 150 ppm to about 800 ppm, about 166 ppm to about 800 ppm, about 200 ppm to about 800 ppm, about 250 ppm to about 800 ppm, about 270 ppm to about 800 ppm, about 300 ppm to about 800 ppm, about 350 ppm to about 800 ppm, about 400 ppm to about 800 ppm, about 450 ppm to about 800 ppm, about 500 ppm to about 800 ppm, about 550 ppm to about 800 ppm, about 600 ppm to about 800 ppm, about 650 ppm to about 800 ppm, or about 700 ppm to about 800 ppm of molybdenum, based on the total weight of the composition.

[0127] In certain embodiments, the amount of the one or more molybdenum-containing compounds is to provide the lubricant composition with about 100 ppm to about 400 ppm, about 150 ppm to about 400 ppm, about 166 ppm to about 400 ppm, about 200 ppm to about 400 ppm, about 250 ppm to about 400 ppm, about 270 ppm to about 400 ppm, or about 300 ppm to about 400 ppm of molybdenum based on the total weight of the composition.

[0128] In certain embodiments, the amount of the one or more molybdenum-containing compounds is to provide the lubricant composition with about 800 ppm to about 2000 ppm, about 850 ppm to about 2000 ppm, about 900 ppm to about 2000 ppm, about 950 ppm to about 2000 ppm, about 1000 ppm to about 2000 ppm, about 1100 ppm to about 2000 ppm, about 1200 ppm to about 2000 ppm, or about 1300 ppm to about 2000 ppm of molybdenum, based on the total weight of the composition.

[0129] In certain embodiments, the amount of the one or more molybdenum-containing compounds is to provide the lubricant composition with a ratio of about 1:2, about 1:3, about 1:4, about 1:5, about 1:6, about 1:7, about 1:8, about 1:9, or about 1:10 ppm molybdenum to ppm calcium based on the total weight of the composition.

[0130] In certain embodiments, the amount of molybdenum in the lubricant composition is proportional to the amount of calcium in the lubricant composition. In certain embodiments, the amount of one or more molybdenum-containing compounds is such as to provide a lubricant composition with a molybdenum-containing compound in the range of about 1:2 to about 1:3, about 1:2 to about 1:4, about 1:2 to about 1:5, about 1:2 to about 1:6, about 1:2 to about 1:7, about 1:2 to about 1:8, about 1:2 to about 1:9, about 1:2 to about 1:10, about 1:3 to about 1:4, about 1:3 to about 1:5, about 1:3 to about 1:6, about 1:2 to about 1:7, about 1:2 to about 1:8, about 1:2 to about 1:9, about 1:2 to about 1:10, about 1:3 to about 1:4, about 1:3 to about 1:5, about 1:3 to about 1:6, about 1:3 to about 1:7, about 1:3 to about 1:8, about 1:3 to about 1:9, about 1:3 to about 1:10, about 1:4 to about 1:5 1:6, about 1:4 to about 1:7, about 1:4 to about 1:8, about 1:4 to about 1:9, about 1:4 to about 1:10, about 1:5 to about 1:6, about 1:5 to about 1:7, about 1:5 to about 1:8, about 1:5 to about 1:9, about 1:5 to about 1:10, about 1:6 to about 1:7, about 1:6 to about 1:8, about 1:6 to about 1:9, about 1:6 to about 1:10, about 1:7 to about 1:8, about 1:7 to about 1:9, about 1:7 to about 1:10, about 1:8 to about 1:9, about 1:8 to about 1:10, and about 1:9 to about 1:10 ppm molybdenum to calcium ppm.

[0131] In certain embodiments, the amount of the one or more molybdenum-containing compounds provides the lubricant composition with at least about 850 ppm of molybdenum, based on the total weight of the composition; and the amount of the one or more calcium detergents provides the lubricant composition with at least about 1800 ppm of calcium, based on the total weight of the composition.

[0132] In certain embodiments, the amount of the one or more molybdenum-containing compounds provides the lubricant composition with at least about 100 ppm to about 850 ppm of molybdenum, based on the total weight of the composition; and the amount of the one or more calcium detergents provides the lubricant composition with at least about 1000 to about 1450 ppm of calcium, based on the total weight of the composition.

[0133] Calcium detergent

[0134] Calcium detergents for use in the lubricant compositions of the present disclosure include, but are not limited to, calcium sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates, naphthenates, and other carboxylates. In certain embodiments, the calcium detergent is neutral and / or overbased.

[0135] In certain embodiments, the one or more calcium detergents comprise or consist essentially of calcium sulfonate. In certain embodiments, the one or more calcium detergents comprise or consist essentially of calcium phenate. In certain embodiments, the one or more calcium detergents comprise or consist essentially of calcium phenate. In certain embodiments, the one or more calcium detergents comprise or consist essentially of calcium sulfonate. In certain embodiments, the one or more calcium detergents comprise or consist essentially of calcium thiophosphonate. In certain embodiments, the one or more calcium detergents comprise or consist essentially of calcium salicylate. In certain embodiments, the one or more calcium detergents comprise or consist essentially of calcium cyclohexaneate. In certain embodiments, the one or more calcium detergents comprise or consist essentially of calcium carboxylate. In certain embodiments, the carboxylate is a salicylate.

[0136] In certain embodiments, the lubricant composition comprises two or more types of calcium detergents.

[0137] In certain embodiments, the calcium detergent may be present in an amount to provide the lubricant composition with about 600 ppm to about 3500 ppm, or about 600 ppm to about 2400 ppm, about 800 ppm to about 1800, about 1200 ppm to about 1800 ppm, about 1800 ppm to about 2400 ppm, or about 1800 ppm to about 3500 ppm of calcium.

[0138] In certain embodiments, the calcium detergent may be present in an amount to provide at least about 600 ppm, 800 ppm, 1000 ppm, 1200 ppm, 1400 ppm, 1600 ppm, 1800 ppm, 2000 ppm, 2200 ppm, 2400 ppm, 2600 ppm, 2800 ppm, or 3000 ppm of calcium to the lubricant composition.

[0139] Oil of lubricating viscosity

[0140] The oil of lubricating viscosity (also referred to as base oil) used in the lubricant composition of the present disclosure is typically present in a major amount, such as an amount greater than about 50% by weight, greater than about 60% by weight, greater than about 70% by weight, greater than about 80% by weight, or about 60 to about 99.5% by weight, about 70 to about 99.5% by weight, about 80 to about 99.5% by weight, about 85 to about 99.5% by weight, about 60 to about 98% by weight, about 70 to about 98% by weight, about 80 to about 98% by weight, or about 85 to about 98% by weight, based on the total weight of the composition. The expression "base oil" as used herein is understood to mean a base stock or base stock mixture produced according to selected specifications (regardless of the feed source or manufacturer location). The base oil used herein can be any currently known or later discovered oil of lubricating viscosity for use in formulating lubricant compositions for any and all such applications, such as engine oils, marine cylinder oils, functional fluids such as hydraulic oils, gear oils, transmission fluids, and the like.

[0141] As will be readily appreciated by those skilled in the art, the viscosity of the base oil will depend on the application.Thus, the viscosity of the base oils used herein will generally range from about 2 to about 2000 centistokes (cSt) at 100°C. Typically, base oils used alone as engine oils will have a kinematic viscosity at 100°C in the range of from about 2 cSt to about 30 cSt, preferably from about 3 cSt to about 16 cSt and most preferably from about 4 cSt to about 12 cSt, and will be selected or blended depending on the desired end use and additives in the finished oil to provide the desired grade of engine oil, such as lubricant compositions having SAE viscosity grades of 0W, 0W-8, 0W-12, 0W-16, 0W-20, 0W-26, 0W-30, 0W-40, 0W-50, 0W-60, 5W, 5W-20, 5W-30, 5W-40, 5W-50, 5W-60, 10W, 10W-20, 10W-30, 10W-40, 10W-50, 15W, 15W-20, 15W-30, 15W-40, 30, 40, etc. In one embodiment, the lubricant composition has an SAE viscosity grade of 0W-20 or 0W-40.

[0142] Group I base oils generally refer to petroleum-derived lubricating base oils having a saturates content of less than 90 weight percent (as measured by ASTM D2007) and / or a total sulfur content greater than 300 ppm (as measured by ASTM D 2622, ASTM D 4294, ASTM D 4297, or ASTM D 3120) and a viscosity index (VI) greater than or equal to 80 and less than 120 (as measured by ASTM D 2270).

[0143] Group II base oils generally refer to petroleum-derived lubricating base oils having a total sulfur content equal to or less than 300 parts per million (ppm) (as measured by ASTM D 2622, ASTM D 4294, ASTM D 4927, or ASTM D 3120), a saturates content equal to or greater than 90 weight percent (as measured by ASTM D 2007), and a viscosity index (VI) between 80 and 120 (as measured by ASTM D 2270).

[0144] Group III base oils generally refer to petroleum-derived lubricating base oils having less than 300 ppm sulfur, a saturate content greater than 90 weight percent, and a VI of 120 or greater.

[0145] Group IV base oils are polyalphaolefins (PAO).

[0146] Group V base oils include all other base oils not included in Groups I, II, III or IV.

[0147] In one embodiment, the lubricant composition comprises one or more Group I base oils. In one embodiment, the lubricant composition comprises one or more Group II base oils. In one embodiment, the lubricant composition comprises one or more Group III base oils. In one embodiment, the lubricant composition comprises one or more Group IV base oils. In one embodiment, the lubricant composition comprises one or more Group V base oils. In one embodiment, the lubricant composition comprises one or more Group II or Group III base oils.

[0148] The lubricant composition may contain small amounts of other base oil components. For example, the lubricant composition may contain small amounts of base oils derived from natural lubricants, synthetic lubricants, or mixtures thereof. Suitable base oils include base stocks obtained by isomerization of synthetic waxes and slack waxes, and hydrocracked base stocks produced by hydrocracking (rather than solvent extraction) the aromatic and polar components of crude oil.

[0149] Suitable natural oils include mineral lubricants such as, for example, liquid petroleum oils, solvent-treated or acid-treated mineral lubricants of the paraffinic, naphthenic or mixed paraffinic-naphthenic types, oils derived from coal or shale, animal oils, vegetable oils (e.g., rapeseed oil, castor oil and lard), and the like.

[0150] Suitable synthetic lubricants include, but are not limited to, hydrocarbon oils and halo-substituted hydrocarbon oils such as polymeric and interpolymeric olefins, e.g., polybutene, polypropylene, propylene-isobutylene copolymers, chlorinated polybutene, poly(1-hexene), poly(1-octene), poly(1-decene), etc., and mixtures thereof; alkylbenzenes, such as dodecylbenzene, tetradecylbenzene, dinonylbenzene, di(2-ethylhexyl)-benzene, etc.; polyphenyls, such as biphenyls, terphenyls, alkylated polyphenyls, etc.; alkylated diphenyl ethers and alkylated diphenyl sulfides, and derivatives, analogs, and homologs thereof, etc.

[0151] Other synthetic lubricants include, but are not limited to, oils made by polymerizing olefins having less than 5 carbon atoms, such as ethylene, propylene, butylene, isobutylene, pentene, and mixtures thereof. Methods for preparing such polymer oils are well known to those skilled in the art.

[0152] Other synthetic hydrocarbon oils include liquid polymers of alpha olefins of suitable viscosity. Particularly useful synthetic hydrocarbon oils are C6 to C 12 Hydrogenated liquid oligomers of alpha olefins, such as, for example, 1-decene trimer.

[0153] Another class of synthetic lubricants includes, but is not limited to, alkylene oxide polymers, i.e., homopolymers, interpolymers, and derivatives thereof in which the terminal hydroxyl groups have been modified, for example, by esterification or etherification. These oils are exemplified by oils prepared by the polymerization of ethylene oxide or propylene oxide, alkyl ethers and phenyl ethers of these polyoxyalkylene polymers (e.g., methyl polypropylene glycol ether with an average molecular weight of 1,000, diphenyl ether of polyethylene glycol with a molecular weight of 500-1000, diethyl ether of polypropylene glycol with a molecular weight of 1,000-1,500, etc.) or their mono- and polycarboxylic acid esters (such as, for example, acetate of tetraethylene glycol, mixed C3-C8 fatty acid esters, or C 13 Oxygen acid diester).

[0154] Yet another class of synthetic lubricants includes, but is not limited to, esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkylsuccinic acid, alkenylsuccinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acid, alkenylmalonic acid, etc.) with various alcohols (e.g., butanol, hexanol, dodecanol, 2-ethylhexanol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc.) Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, 2-ethylhexyl diester of linoleic acid dimer, complex esters formed by reacting 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid, and the like.

[0155] Esters useful as synthetic oils also include, but are not limited to, those made from carboxylic acids having from about 5 to about 12 carbon atoms and alcohols (e.g., methanol, ethanol, etc.), polyols, and polyol ethers (such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, etc.).

[0156] Silicon-based oils, such as, for example, polyalkyl-, polyaryl-, polyalkoxy- or polyaryloxy-siloxane oils and silicate oils, constitute another class of useful synthetic lubricants. Specific examples of these include, but are not limited to, tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-hexyl) silicate, tetra-(p-tert-butylphenyl) silicate, hexyl-(4-methyl-2-pentyloxy) disiloxane, poly(methyl)siloxane, poly(methylphenyl)siloxane, and the like. Still other useful synthetic lubricants include, but are not limited to, liquid esters of phosphoric acid, such as tricresyl phosphate, trioctyl phosphate, diethyl decanephosphinate, and the like, polymeric tetrahydrofuran, and the like.

[0157] Lubricant can be derived from unrefined, refined and re-refined oil, and it is natural, synthetic or the mixture of any two or more of these types disclosed above.Unrefined oil is to obtain directly from natural or synthetic source (such as coal, shale or tar sands pitch) and without further purification or those of processing.The example of unrefined oil includes but is not limited to the shale oil directly obtained from retorting operation, the petroleum oil directly obtained from distillation or the ester oil directly obtained from esterification process, each of which can be used without further processing then.Refined oil is similar to unrefined oil, except that they are further processed to improve one or more characteristics in one or more purification steps.These purification techniques are well known to those skilled in the art, and comprise for example solvent extraction, secondary distillation, acid or alkali extraction, filtration, percolation, hydrotreating, dewaxing etc.Re-refined oil is to obtain by processing used oil in the process similar to the process for obtaining refined oil.This type of re-refined oil is also referred to as regenerated oil or reprocessed oil, and usually carries out additional processing by being intended to the technology of removing waste additives and oil decomposition products.

[0158] Lubricant base stocks obtained by hydroisomerization of waxes may also be used alone or in combination with the above-mentioned natural and / or synthetic base stocks. Such wax isomerized oils are produced by hydroisomerizing natural waxes or synthetic waxes or mixtures thereof over a hydroisomerization catalyst.

[0159] Natural waxes are typically slack waxes recovered by solvent dewaxing of mineral oils; synthetic waxes are typically waxes produced by the Fisher-Tropsch process.

[0160] Other useful fluids of lubricating viscosity include non-conventional or unconventional base stocks that have been processed (preferably catalytically processed) or synthesized to provide high performance lubricating properties.

[0161] Lubricant additives

[0162] Typically, the lubricant composition of the present disclosure may include additional lubricant additives. The lubricant composition of the present disclosure may also contain other conventional additives, such as those that can impart or improve any desired properties of the lubricant composition in which these additives are dispersed or dissolved. Any additive known to those of ordinary skill in the art can be used in the lubricant composition disclosed herein. Mortier et al., "Chemistry and Technology of Lubricants", 2nd edition, London, Springer, (1996); and Leslie R. Rudnick, "Lubricant Additives: Chemistry and Applications", New York, Marcel Dekker (2003) describe some suitable additives, both of which are incorporated herein by reference. For example, the lubricant composition can be blended with antioxidants, antiwear agents, metal detergents, rust inhibitors, demisters, demulsifiers, metal deactivators, friction modifiers, pour point depressants, defoamers, cosolvents, corrosion inhibitors, ashless dispersants, multifunctional agents, dyes, extreme pressure agents, and the like, and mixtures thereof. A variety of additives are known and commercially available. These additives or their similar compounds can be used to prepare the lubricant compositions of the present disclosure by conventional blending procedures.

[0163] In addition to calcium detergents, the lubricant compositions of the present disclosure may also contain one or more non-calcium detergents, such as other metal-containing or ash-forming detergents. Metal-containing or ash-forming detergents can be used as detergents to reduce or remove deposits and as acid neutralizers or rust inhibitors, thereby reducing wear and corrosion and extending engine life. Detergents generally contain a polar head with a long hydrophobic tail. The polar head comprises a metal salt of an acidic organic compound. The salt can contain a substantially stoichiometric amount of metal, in which case they are generally described as normal salts or neutral salts. Large amounts of metal base can be incorporated by reacting an excess of a metal compound (e.g., an oxide or hydroxide) with an acidic gas (e.g., carbon dioxide).

[0164] Detergents which may be used include oil-soluble neutral and overbased sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates and naphthenates of metals, particularly the alkali or alkaline earth metals such as barium, sodium, potassium, lithium and magnesium, and other oil-soluble carboxylates.

[0165] In one embodiment, the lubricant composition includes one or more magnesium detergents. In one embodiment, the one or more magnesium detergents may be added in an amount sufficient to provide the lubricant composition with about 100 to about 1000 ppm of magnesium metal, or about 100 to about 600 ppm, or about 100 to about 500 ppm, or about 200 to about 500 ppm of magnesium metal in the lubricant composition. In certain embodiments, the lubricant composition does not contain a magnesium detergent or a magnesium-containing compound.

[0166] In one embodiment, the lubricant composition includes one or more lithium detergents. In one embodiment, the one or more lithium detergents may be added in an amount sufficient to provide the lubricant composition with 0 to about 2400 ppm lithium metal, 0 to about 2200 ppm lithium metal, 100 to about 2000 ppm lithium metal, 200 to about 1800 ppm lithium metal, or about 100 to about 1800 ppm, or about 200 to about 1500 ppm, or about 300 to about 1400 ppm, or about 400 to about 1400 ppm lithium metal in the lubricant composition.

[0167] In one embodiment, the lubricant composition comprises one or more sodium detergents. In one embodiment, the one or more sodium detergents may be added in an amount sufficient to provide the lubricant composition with 0 to about 2400 ppm sodium metal, 0 to about 2200 ppm sodium metal, 100 to about 2000 ppm sodium metal, 200 to about 1800 ppm sodium metal, or about 100 to about 1800 ppm, or about 200 to about 1500 ppm, or about 300 to about 1400 ppm, or about 400 to about 1400 ppm sodium metal in the lubricant composition.

[0168] In one embodiment, the lubricant composition comprises one or more potassium detergents. In one embodiment, the one or more potassium detergents may be added in an amount sufficient to provide the lubricant composition with 0 to about 2400 ppm potassium metal, 0 to about 2200 ppm potassium metal, 100 to about 2000 ppm potassium metal, 200 to about 1800 ppm potassium metal, or about 100 to about 1800 ppm, or about 200 to about 1500 ppm, or about 300 to about 1400 ppm, or about 400 to about 1400 ppm potassium metal in the lubricant composition.

[0169] Lubricant composition of the present invention can contain one or more antiwear agents that can reduce friction and excessive wear.Any antiwear agent known to those of ordinary skill in the art can be used in lubricant composition.The limiting examples of suitable antiwear agent comprises metal (such as Pb, Sb, Mo etc.) salt of zinc dithiophosphate, dithiophosphoric acid, metal (such as Zn, Pb, Sb, Mo etc.) salt of dithiocarbamic acid, metal (such as Zn, Pb, Sb etc.) salt of fatty acid, boron compound, phosphoric acid ester, phosphite, phosphate or thiophosphate amine salt, reaction product of dicyclopentadiene and thiophosphoric acid and combination thereof.Based on the gross weight of lubricant composition, the amount of antiwear agent can change from approximately 0.01 % by weight to approximately 5 % by weight, approximately 0.05 % by weight to approximately 3 % by weight or approximately 0.1 % by weight to approximately 1 % by weight.

[0170] In certain embodiments, the antiwear agent is or includes a dialkyl dithiophosphate metal salt, such as a zinc dialkyl dithiophosphate compound. The metal of the dialkyl dithiophosphate metal salt can be an alkali metal or an alkaline earth metal, or aluminum, lead, tin, molybdenum, manganese, nickel or copper. In some embodiments, the metal is zinc. In other embodiments, the alkyl group of the dialkyl dithiophosphate metal salt has from about 3 to about 22 carbon atoms, from about 3 to about 18 carbon atoms, from about 3 to about 12 carbon atoms or from about 3 to about 8 carbon atoms. In further embodiments, the alkyl group is straight or branched.

[0171] The amount of metal dihydrocarbyl dithiophosphate salt, including zinc dialkyl dithiophosphate salt, in the lubricant compositions disclosed herein is measured by its phosphorus content. In some embodiments, the phosphorus content of the lubricant compositions disclosed herein is from about 0.01 wt % to about 0.14 wt %, based on the total weight of the lubricant composition.

[0172] The lubricant composition of the present invention may contain one or more friction modifiers that can reduce friction between moving parts. Any friction modifier known to those of ordinary skill in the art can be used in the lubricant composition. Non-limiting examples of suitable friction modifiers include fatty carboxylic acids; derivatives of fatty carboxylic acids (e.g., alcohols, esters, borated esters, amides, metal salts, etc.); mono-, di- or tri-alkyl substituted phosphoric or phosphonic acids; derivatives of mono-, di- or tri-alkyl substituted phosphoric or phosphonic acids (e.g., esters, amides, metal salts, etc.); mono-, di- or tri-alkyl substituted amines; mono- or di-alkyl substituted amides and combinations thereof. In some embodiments, examples of friction modifiers include, but are not limited to, alkoxylated fatty amines; borated fatty epoxides; fatty phosphites; fatty epoxides, fatty amines, borated alkoxylated fatty amines, fatty acid metal salts, fatty acid amides, glycerides, borated glycerides; and fatty imidazolines, as disclosed in U.S. Patent No. 6,372,696, the contents of which are incorporated herein by reference; C4 to C 75 , or C6 to C 24 , or C6 to C 20 A friction modifier obtained by the reaction product of a fatty acid ester and a nitrogen-containing compound selected from the group consisting of ammonia, alkanolamines, and the like, and mixtures thereof. The amount of the friction modifier can vary from about 0.01 wt % to about 10 wt %, from about 0.05 wt % to about 5 wt %, or from about 0.1 wt % to about 3 wt %, based on the total weight of the lubricant composition.

[0173] The lubricant composition of the present invention may contain an organic oxidation inhibitor in an amount of 0.01 to 5% by weight, preferably 0.1 to 3% by weight. The oxidation inhibitor may be a hindered phenol oxidation inhibitor or a diarylamine oxidation inhibitor. Diarylamine oxidation inhibitors are advantageous in providing a base value derived from nitrogen atoms. Hindered phenol oxidation inhibitors are advantageous in preventing the generation of NOx gas.

[0174] Examples of hindered phenol oxidation inhibitors include 2,6-di-tert-butyl-p-cresol, 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(6-tert-butyl-o-cresol), 4,4'-isopropylidenebis(2,6-di-tert-butylphenol), 4,4'-bis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-thiobis(2 6-tert-butylphenol), 2,2-thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and commercial products such as, but not limited to, Irganox (BASF), Naugalube (Chemtura) and Ethanox (SI Group).

[0175] Examples of diarylamine oxidation inhibitors include alkyldiphenylamines having a mixture of alkyl groups having 4 to 9 carbon atoms, p,p′-dioctyldiphenylamine, phenyl-naphthylamine, phenyl-naphthylamine, alkylated-naphthylamines, and alkylated phenyl-naphthylamines.

[0176] Each of the hindered phenol oxidation inhibitor and the diarylamine oxidation inhibitor may be used alone or in combination. If desired, other oil-soluble oxidation inhibitors may be used in combination with one or more of the above-mentioned oxidation inhibitors.

[0177] In certain embodiments, the lubricant composition comprises a sulfur-containing molybdenum oxycomplex of succinimide as one of the one or more molybdenum-containing compounds and an additive selected from phenolic or amine oxidation inhibitors.

[0178] In the preparation of lubricant formulations, it is common practice to incorporate the additive in the form of a 10% to 80% by weight active ingredient concentrate in a hydrocarbon oil (such as a mineral lubricant) or other suitable solvent.

[0179] Typically, these concentrates can be diluted with 3 to 100 parts by weight, such as 5 to 40 parts by weight, of lubricant per part by weight of the additive package when forming a finished lubricant, such as a crankcase motor oil. The purpose of the concentrates, of course, is to make the handling of the various materials less difficult and awkward and to facilitate dissolution or dispersion in the final blend.

[0180] Generally, the sulfur level in the lubricant composition of the present invention is less than or equal to about 0.7 wt %, based on the total weight of the lubricant composition, such as a sulfur level of about 0.01 wt % to about 0.70 wt %, 0.01 to 0.6 wt %, 0.01 to 0.5 wt %, 0.01 to 0.4 wt %, 0.01 to 0.3 wt %, 0.01 to 0.2 wt %, 0.01 to 0.10 wt %. In one embodiment, the sulfur level in the lubricant composition of the present invention is less than or equal to about 0.60 wt %, less than or equal to about 0.50 wt %, less than or equal to about 0.40 wt %, less than or equal to about 0.30 wt %, less than or equal to about 0.20 wt %, or less than or equal to about 0.10 wt %, based on the total weight of the lubricant composition.

[0181] In one embodiment, the phosphorus level in the lubricant composition of the present invention is less than or equal to about 0.12 wt %, such as a phosphorus level of about 0.01 wt % to about 0.12 wt %, based on the total weight of the lubricant composition. In one embodiment, the phosphorus level in the lubricant composition of the present invention is less than or equal to about 0.11 wt %, such as a phosphorus level of about 0.01 wt % to about 0.11 wt %, based on the total weight of the lubricant composition. In one embodiment, the phosphorus level in the lubricant composition of the present invention is less than or equal to about 0.10 wt %, such as a phosphorus level of about 0.01 wt % to about 0.10 wt %, based on the total weight of the lubricant composition. In one embodiment, the phosphorus level in the lubricant composition of the present invention is less than or equal to about 0.09 wt %, such as a phosphorus level of about 0.01 wt % to about 0.09 wt %. In one embodiment, the phosphorus level in the lubricant composition of the present invention is less than or equal to about 0.08 wt %, such as a phosphorus level of about 0.01 wt % to about 0.08 wt %, based on the total weight of the lubricant composition. In one embodiment, the level of phosphorus in the lubricant composition of the present invention is less than or equal to about 0.07 wt %, such as a level of phosphorus ranging from about 0.01 wt % to about 0.07 wt %, based on the total weight of the lubricant composition. In one embodiment, the level of phosphorus in the lubricant composition of the present invention is less than or equal to about 0.05 wt %, such as a level of phosphorus ranging from about 0.01 wt % to about 0.05 wt %, based on the total weight of the lubricant composition.

[0182] In one embodiment, the lubricant composition of the present invention produces a sulfated ash level of less than or equal to about 1.60 wt % as determined by ASTM D 874, such as a sulfated ash level of about 0.10 to about 1.60 wt % as determined by ASTM D 874. In one embodiment, the lubricant composition of the present invention produces a sulfated ash level of less than or equal to about 1.00 wt % as determined by ASTM D 874, such as a sulfated ash level of about 0.10 to about 1.00 wt % as determined by ASTM D 874. In one embodiment, the lubricant composition of the present invention produces a sulfated ash level of less than or equal to about 0.80 wt % as determined by ASTM D 874, such as a sulfated ash level of about 0.10 to about 0.80 wt % as determined by ASTM D 874. In one embodiment, the sulfated ash level produced by the lubricant composition of the present invention is less than or equal to about 0.60 wt % as determined by ASTM D 874, such as from about 0.10 to about 0.60 wt % as determined by ASTM D 874.

[0183] Suitably, the lubricant composition of the present invention may have a total base number (TBN) of 4 to 15 mg KOH / g (eg, 5 to 12 mg KOH / g, 6 to 12 mg KOH / g, or 8 to 12 mg KOH / g).

[0184] Process for preparing lubricant composition

[0185] The lubricant compositions disclosed herein can be prepared by any method known to those of ordinary skill in the art for preparing lubricants. In some embodiments, the base oil can be blended or mixed with one or more molybdenum-containing compounds and one or more calcium detergents as described herein. Optionally, one or more additional additives can be mixed or blended. Additional additives include commonly known lubricant additives such as antiwear agents, foam inhibitors, friction modifiers, foam inhibitors, pour point depressants, viscosity index improvers, such as polymerized alkyl methacrylates; olefin copolymers, such as ethylene-propylene copolymers or styrene-diene copolymers; and the like, and mixtures thereof.

[0186] The one or more molybdenum-containing compounds and the one or more calcium detergents and optional additives may be blended or mixed separately or simultaneously. In some embodiments, the one or more molybdenum-containing compounds and the one or more calcium detergents and optional additives are blended or mixed separately in one or more additions, and the additions may be made in any order. In other embodiments, the one or more molybdenum-containing compounds and the one or more calcium detergents and additives are blended or mixed simultaneously, optionally in the form of an additive concentrate. In some embodiments, dissolution of the one or more molybdenum-containing compounds, the one or more calcium detergents, or any solid additives in the base oil may be assisted by heating the mixture to a temperature of about 25°C to about 200°C, about 50°C to about 150°C, or about 75°C to about 125°C.

[0187] Any mixing or dispersing equipment known to those of ordinary skill in the art can be used to blend, mix or dissolve the ingredients. Blending, mixing or dissolving can be performed using a blender, a stirrer, a disperser, a mixer (e.g., a planetary mixer and a double planetary mixer), a homogenizer (e.g., a Gaulin homogenizer and a Rannie homogenizer), a mill (e.g., a colloid mill, a ball mill and a sand mill), or any other mixing or dispersing equipment known in the art.

[0188] Application of lubricant composition

[0189] The lubricant compositions disclosed herein may be suitable for use as motor oils (ie, engine oils or crankcase oils) in spark-ignited internal combustion engines, particularly direct-injection, supercharged engines that are susceptible to low-speed pre-ignition.

[0190] The following examples are presented to illustrate embodiments of the present invention, but are not intended to limit the invention to the specific embodiments described. Unless otherwise indicated, all parts and percentages are by weight. All numerical values are approximate. When a numerical range is given, it should be understood that embodiments outside the range still fall within the scope of the present invention. The specific details described in each example should not be interpreted as essential features of the present invention.

[0191] Example

[0192] The following examples are intended for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

[0193] Examples 1-4. Exemplary and Comparative Lubricant Compositions

[0194] Exemplary and comparative lubricant composition formulations contained:

[0195] Group II or Group III base oil,

[0196] a calcium detergent mixture in an amount to provide from about 1197 to about 2000 ppm calcium to the lubricant composition,

[0197] one or more molybdenum compounds selected from the group consisting of molybdenum-amine complexes and molybdenum dithiocarbamates in an amount to provide from about 166 ppm to about 1000 ppm of molybdenum to the lubricant composition,

[0198] a mixture of primary and secondary zinc dialkyl dithiophosphates in an amount to provide from about 757 to about 890 ppm zinc to the lubricant composition,

[0199] Polyisobutenyl succinimide dispersant mixture (borated and ethylene carbonate post-treated),

[0200] foam suppressors, and

[0201] Alkylated diphenylamine antioxidant.

[0202] Example 1 and Comparative Example 1 included salicylate, phenate, and sulfonate calcium detergents as calcium sources, and molybdenum dithiocarbamate as the molybdenum source.

[0203] Examples 2-4 and Comparative Example 2 included phenate and sulfonate calcium detergents as calcium sources and a molybdenum-amine complex as the molybdenum source.

[0204] Certain lubricant compositions also contain a borated organic friction modifier and / or an olefin copolymer or poly(methyl acrylate) viscosity index improver. The friction modifier is not a molybdenum-containing compound.

[0205] Example 1 and Comparative Example 1 contained poly(methyl acrylate) viscosity index improver.

[0206] Certain lubricant compositions also contain one or more magnesium detergents in an amount providing from about 436 to about 473 mg of magnesium to the composition.

[0207] The lubricant compositions were blended to form either 0W-20 (Example 1 and Comparative Example 1) or 0W-40 (Examples 2-4 and Comparative Example 2) viscosity grade oils.

[0208] Table 1 provides the amounts of components other than the base oil in exemplary and comparative lubricant compositions.

[0209] Table 1.

[0210]

[0211] Example 5. Oil aging conditions

[0212] The lubricant compositions were aged according to the operating parameters summarized in Table 2. The aging process was a steady state process and ran for a total of 72 hours. The resulting oil was comparable to an oil aged approximately 5,000 miles under normal driving conditions.

[0213] Table 2.

[0214]

[0215]

[0216] Example 6. LSPI Testing of Aged Oils Containing Exemplary or Comparative Lubricant Compositions

[0217] LSPI events were measured in a Ford 2.0L Ecoboost engine, a turbocharged gasoline direct injection (GDI) engine.

[0218] The Ford Ecoboost engine was run in four approximately 4-hour iterations. The engine was operated at 1750 rpm, 1.7 MPa brake mean effective pressure (BMEP), and a sump temperature of 95°C. The engine was run for 175,000 combustion cycles in each phase, and LSPI events were counted.

[0219] LSPI events are determined by monitoring the peak cylinder pressure (PP) and mass fraction burned (MFB) of the fuel charge in the cylinder. When one or both criteria are met, an LSPI event is said to have occurred. The threshold for peak cylinder pressure varies from test to test, but is typically 4-5 standard deviations above the mean cylinder pressure. Similarly, the MFB threshold is typically 4-5 standard deviations earlier than the mean MFB (expressed in crank angle degrees). LSPI events can be reported as average events per test, events per 100,000 combustion cycles, events per cycle, and / or combustion cycles per event. The results are shown in Table 3.

[0220] Table 3. Ford Used Oil LSPI Test

[0221]

[0222] *All LSPI cycles that met both the MFB02 and peak pressure requirements were counted.

[0223] **The passing limit value is the current standard for GF-6 fresh oil testing.

[0224] The LSPI results for the Ford used oil from Example 1 and Comparative Example 1 show that at high calcium levels (2000 ppm), increasing the amount of molybdenum results in a decrease in the average number of LSPI events from 7.75 to 3.75. Furthermore, a comparison of Examples 3 and 4 also shows that increasing the amount of molybdenum reduces the average number of LSPI events.

Claims

1. A method for preventing or reducing low speed pre-ignition (LSPI) in a direct injection, supercharged, spark ignition internal combustion engine, the method comprising the step of lubricating the engine with a used or aged lubricant composition comprising: (i) one or more oils of lubricating viscosity; (ii) one or more molybdenum-containing compounds in an amount to provide the lubricant composition with at least about 100 ppm of molybdenum based on the total weight of the composition; and (iii) one or more calcium detergents in an amount to provide the lubricant composition with at least about 1000 ppm calcium based on the total weight of the composition; wherein the used or aged lubricant composition lubricates the engine during at least one oil change interval.

2. The method of claim 1 , wherein the amount of (ii) the one or more molybdenum-containing compounds provides the lubricant composition with at least about 850 ppm of molybdenum, based on the total weight of the composition; and the amount of (iii) the one or more calcium detergents provides the lubricant composition with at least about 1800 ppm of calcium, based on the total weight of the composition.

3. The method of claim 1 , wherein the amount of (ii) the one or more molybdenum-containing compounds provides the lubricant composition with about 100 ppm to about 850 ppm of molybdenum, based on the total weight of the composition; and the amount of (iii) the one or more calcium detergents provides the lubricant composition with about 1000 to about 1450 ppm of calcium, based on the total weight of the composition.

4. The method of claim 1, wherein the amount of said and said (iii) one or more calcium detergents provides said lubricant composition with less than about 2400 ppm based on the total weight of said composition.

5. The method of claim 1, wherein the one or more molybdenum-containing compounds are selected from the group consisting of molybdenum-amine complexes, molybdenum dithiophosphates, and molybdenum dithiocarbamates.

6. The method of claim 1, wherein the one or more molybdenum-containing compounds are selected from the group consisting of molybdenum-amine complexes and molybdenum dithiophosphates.

7. The method of claim 6, wherein the molybdenum-amine complex is a molybdenum succinimide complex.

8. The method of claim 1, wherein the direct injection, supercharged, spark ignition internal combustion engine is a downsized engine or an engine in the size range of 0.5 liters to 3.6 liters.

9. The method of claim 1, wherein the direct injection, supercharged, spark ignition internal combustion engine is operated at a speed of 500 to 3000 rpm.

10. The method of claim 1, wherein the direct injection, supercharged, spark ignition internal combustion engine is operated at a load having a brake mean effective pressure (BMEP) of about 12 to about 30 bar.

11. The method of claim 1 wherein said LSPI events occur less than 10 times per 100,000 combustion events while said engine is operating.

12. The method of claim 1, wherein the method reduces the number of LSPI events by at least 50%.

13. The method of claim 1, wherein the one or more calcium detergents are selected from the group consisting of carboxylate detergents.

14. The method of claim 1, wherein the one or more calcium detergents are selected from the group consisting of salicylate, phenate, or sulfonate detergents.

15. The method of claim 1, wherein the lubricant composition further comprises at least one other additive selected from the group consisting of ashless dispersants, antioxidants, anti-wear additives, friction modifiers, and polymeric viscosity modifiers.

16. The method of claim 1, wherein the at least one oil change interval is at least 3,000 miles.

17. The method of claim 1, wherein the at least one oil change interval is at least 5,000 miles.

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