Method for preventing or reducing low speed preignition in direct injection spark ignition engines using molybdenum-containing lubricant compositions

Abstract

Lubricant compositions for direct-injection, supercharged, spark-ignition internal combustion engines are disclosed, including one or more molybdenum-containing compounds and one or more calcium-based detergents. The disclosure also relates to methods for reducing or preventing low-speed pre-ignition (LSPI) over the course of at least one oil change interval.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 378,599, filed October 6, 2022, the entire contents of which are incorporated herein by reference.

[0002] This disclosure relates to lubricant compositions for direct-injection, supercharged, spark-ignition internal combustion engines containing a molybdenum-containing compound and a calcium-based detergent. This disclosure also relates to methods for preventing or reducing low-speed preignition in engines lubricated with the formulated oils. [Background technology]

[0003] Modern engine designs are geared towards improving fuel economy without sacrificing performance or durability. Traditionally, gasoline is port injected (PFI), meaning it is injected through the intake port and enters the combustion chamber through the intake valve. Gasoline direct injection (GDI) injects gasoline directly into the combustion chamber.

[0004] Under certain circumstances, abnormal combustion can occur in an internal combustion engine. In a spark-ignition internal combustion engine, abnormal combustion can be understood as an uncontrolled explosion in the combustion chamber caused by a combustible element igniting due to a source other than the ignition system.

[0005] Preignition can be understood as abnormal combustion caused by the ignition of an air-fuel mixture prior to ignition by an ignition device. If the air-fuel mixture in the combustion chamber is ignited prior to ignition by an ignition device, this can be considered preignition.

[0006] Without being bound by any particular theory, preignition traditionally occurs during high-speed engine operation when a specific point within the combustion chamber of a cylinder becomes hot enough to effectively act as a glow plug (e.g., a hot spark plug tip, a hot metal protrusion), providing an ignition source that ignites the air-fuel mixture prior to ignition by the ignition system. This type of preignition is often referred to as hot spot preignition, and can be suppressed simply by identifying and eliminating the hot spot.

[0007] More recently, vehicle manufacturers have been finding that turbocharged gasoline engines suffer from intermittent abnormal combustion, particularly at low speeds and medium-to-high loads. More specifically, when engines are operated at speeds below 3000 rpm and under a load of 10 bar or greater, a condition known as low-speed pre-ignition (LSPI) can occur randomly and stochastically. Furthermore, the tendency for LSPI to occur is linked to engine oil formulations, with the incidence of LSPI increasing as engine oil ages.

[0008] While some engine knocking and pre-ignition problems can and are still being solved through the use of new engine technologies such as electronic controls and knock sensors, or by optimizing engine operating conditions, there is also a role for lubricant compositions that can mitigate or prevent the problem.

[0009] The disclosed engine oil lubricants are suitable for reducing, suppressing, 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 at the beginning of use, but their performance deteriorates dramatically over time. In stark contrast, the disclosed engine oil lubricants are particularly suitable for maintaining their LSPI reduction capabilities throughout their normal service life. Summary of the Invention

[0010] In one aspect, the present disclosure provides a method for reducing or preventing low speed pre-ignition (LSPI) in a direct injection, supercharged, spark ignition internal combustion engine, the method 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 molybdenum, based on the total weight of the composition; and (iii) lubricating an engine with a used or aged lubricant composition comprising one or more calcium-based detergents in an amount providing the lubricant composition with at least about 1000 ppm of calcium, based on the total weight of the composition; A method is provided in which a used or aged lubricant composition lubricates an engine over the course of at least one oil change interval.

[0011] 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.

[0012] In certain embodiments, the one or more molybdenum-containing compounds are in an amount providing the lubricant composition with at least about 850 ppm of molybdenum, based on the total weight of the composition, and the one or more calcium-based detergents are in an amount providing the lubricant composition with at least about 1800 ppm of calcium, based on the total weight of the composition.

[0013] In other embodiments, the one or more molybdenum-containing compounds are in an amount providing 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 one or more calcium-based detergents are in an amount providing the lubricant composition with at least about 1000 to about 1450 ppm of calcium, based on the total weight of the composition. DETAILED DESCRIPTION OF THE INVENTION

[0014] definition The following definitions are provided to more clearly define the terms used herein. Unless otherwise stated, the following definitions are applicable to the present disclosure. When a term is used in this disclosure but is not specifically defined herein, a definition from the IUPAC Compendium of Chemical Terminology may be applied, provided that such definition does not conflict with any other disclosure or definition applied herein or render any claim to which that definition applies unclear or unacceptable. In the event that any definition or usage set forth in any document incorporated by reference herein conflicts with the definition or usage set forth herein, the definition or usage set forth herein shall control.

[0015] Although compositions and methods are described in terms of "comprising" various components or steps, the compositions and methods may "consist essentially of" or "consist of" the various components or steps, unless otherwise specified.

[0016] The terms "a," "an," and "the" are intended to include plural alternatives, e.g., at least one. As used herein, the terms "including," "and," and "having" are defined as inclusive (i.e., open language) unless otherwise specified.

[0017] Various numerical ranges are disclosed herein. When applicant discloses or claims any type of range, applicant's intent, unless otherwise specified, is to disclose or claim individually each numerical value that such range can reasonably encompass, including the endpoints of the range, and all subranges and combinations of subranges encompassed therein. For example, all endpoints of numerical ranges disclosed herein are approximations unless expressly excluded.

[0018] By "major amount" is meant greater than 50% by weight of the composition.

[0019] "Minor amount" means less than 50% by weight of the composition.

[0020] When used in connection with metal-based detergents, the term "overbased" is used to refer to a metal salt in which there is a stoichiometrically greater amount of metal than there is organic radical.

[0021] As referred to herein, the term "ppm" means parts per million by weight based on the total weight of the lubricant composition.

[0022] 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.

[0023] The terms "used" or "aged" with respect to a lubricant composition mean that the lubricant is not fresh. A used or aged lubricant composition generally has 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, a used lubricant composition has been used within at least one oil change interval or over a vehicle mileage of at least about 3,000, 4,000, 5,000, 6,000, 7,000, or 8,000 miles. In certain embodiments, the used lubricant composition is used when the vehicle has traveled from about 3,000 to about 20,000 miles, from about 4,000 to about 20,000 miles, from about 5,000 to about 20,000 miles, from about 6,000 to about 20,000 miles, from about 7,000 to about 20,000 miles, from about 8,000 to about 20,000 miles, from about 3,000 to about 15,000 miles, from about 4,000 to about 15,000 miles, or from about 5,000 to about 15,000 miles. The fuel consumption is about 100% or more, and the fuel consumption is about 15,000 to about 15,000 miles, about 2000 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.

[0024] In some embodiments, the used or aged lubricant composition has been used or aged for at least 1,000 miles, e.g., 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.

[0025] In certain embodiments, the used or aged properties of a lubricant composition may be simulated for testing purposes, i.e., the lubricant composition may be artificially aged by simulating use conditions in an engine. For example, an artificially aged lubricant composition for testing may be produced by iron-catalyzed oxidation according to GFC Lu-43A-11 method at a temperature ranging from about 150°C to 170°C for a period of about 110 hours to 150 hours. In certain embodiments, the properties of a used or aged lubricant composition may be simulated, for example, as described in Example 6, to provide a lubricant composition equivalent to a lubricant composition that has been used under normal driving conditions for a desired mileage of, for example, 5000 miles.

[0026] The term "supercharging" is used throughout this specification. Supercharging refers to operating an engine at a higher intake pressure than a naturally aspirated engine. Supercharging can be achieved using a turbocharger (driven by the exhaust) or a supercharger (driven by the engine). The use of smaller engines that offer higher power density has enabled engine manufacturers to provide superior performance while reducing friction and pumping losses. This is achieved by increasing the boost pressure using a turbocharger or mechanical supercharger, and by reducing engine speed using a higher transmission ratio, which allows for higher torque generation at lower engine speeds. However, it has been found that higher torque at lower engine speeds can cause LSPI events, resulting in very high peak cylinder pressures and potentially catastrophic engine failure. Due to the potential for LSPI, engine manufacturers cannot fully optimize engine torque at lower engine speeds in these smaller, high-power engines.

[0027] The terms "oil-soluble" or "oil-dispersible" mean that a given amount required to impart a 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 wt. % of the material can be incorporated into a lubricant composition. For further discussion of oil-solubility and dispersibility, particularly the term "stably dispersible," see U.S. Pat. No. 4,320,019, which is expressly incorporated herein by reference for relevant teachings in this regard.

[0028] As used herein, the term "sulfated ash" refers to the non-burnable residue resulting from detergents and metallic additives in a lubricant. Sulfated ash may be determined using ASTM test D874.

[0029] 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 number reflects more alkalinity and, therefore, more alkalinity. TBN was determined using the ASTM D2896 test.

[0030] Unless otherwise specified, all percentages are by weight.

[0031] As used herein, the term "alkyl" means, unless otherwise specified, C1-C 24The term includes saturated linear, branched, cyclic, primary, secondary, or tertiary hydrocarbons. This term includes both substituted and unsubstituted alkyl groups. The moiety that the alkyl group can be substituted with 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, as is well known to those skilled in the art, for example, as taught in Greene, et al., Protective Groups in Organic Synthesis, John Wiley and Sons, Second Edition, 1991, and is incorporated herein by reference. When an alkyl group is substituted with an alkyl group, this is used synonymously with the term "branched alkyl group." Specific examples of alkyl and / or substituted alkyl include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, t-butyl, n-pentyl, iso-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, stearyl, icosyl, 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, myristyl, palmityl, and stearyl.

[0032] The term "cycloalkyl" or "cyclic alkyl" refers to a type of alkyl containing 3 to 15 carbon atoms, containing one or more rings, without alternating or resonating double bonds between carbon atoms. This term includes both substituted and unsubstituted cycloalkyl groups. The moieties with which a cycloalkyl group can be substituted are 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, whether unprotected or optionally protected, as known to those skilled in the art and taught, for example, in Greene, et al., Protective Groups in Organic Synthesis, John Wiley and Sons, Second Edition, 1991, incorporated herein by reference. For example, cycloalkyls include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. In certain embodiments, cycloalkyls contain 1 to 4 rings, which may be fused. In certain embodiments, cycloalkyl groups may contain one or more double or triple bonds in one or more rings.

[0033] The term "alkenyl" includes straight-chain, branched, or cyclic hydrocarbon radicals containing 2 to 10 carbon atoms and at least one carbon-carbon double bond. Examples of alkenyl groups include ethenyl, propenyl, butenyl, and cyclohexenyl.

[0034] Although any processes and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, exemplary processes and materials are described herein.

[0035] All publications and patents mentioned herein are incorporated by reference for the purpose of describing and disclosing, for example, structures and methodologies described in the publications that might be used in connection with the presently described invention. The publications discussed throughout the text are provided solely for their disclosure prior to the filing date of the present application. Nothing herein should be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.

[0036] Lubricant Compositions and Methods The present disclosure generally relates to a method for reducing or preventing low-speed preignition (LSPI) events in a direct-injection, supercharged, spark-ignition internal combustion engine during or between oil change intervals. In another aspect, the disclosure provides a method for maintaining the low-speed preignition reduction capabilities of a used or aged lubricant composition in a direct-injection, supercharged, spark-ignition internal combustion engine. The lubricant composition for use in the method according to the present invention includes (i) one or more oils of lubricating viscosity, (ii) one or more molybdenum-containing compounds, and (iii) one or more calcium-based detergents. This exemplary lubricant composition is suitable for reducing, preventing, suppressing, or eliminating LSPI events in a direct-injection, supercharged, spark-ignition internal combustion engine using a used or aged lubricant composition.

[0037] While lubricant compositions provide LSPI reduction when freshly or newly applied to an engine crankcase, such properties may deteriorate with use or aging. Pre-ignition may be exacerbated by used or aged lubricant compositions. Applicant has discovered that lubricant compositions according to embodiments maintain their LSPI reduction capabilities with use or aging, i.e., over extended periods of time. By using methods according to the present invention, exemplary lubricant compositions may be used to prevent or reduce LSPI in direct-injection, supercharged, spark-ignition internal combustion engines over extended periods of use without substantial loss of performance. Substituting lubricant compositions according to the present invention for comparative lubricant compositions may reduce the need to replace lubricant compositions in an engine to reduce LSPI.

[0038] Low-speed pre-ignition is most likely to occur in direct-injection, turbocharged, or supercharged spark-ignition (gasoline) internal combustion engines that, during operation, produce brake mean effective pressure (BMEP) levels of at least about 15 bar (peak torque), at least about 18 bar, or at least about 20 bar at engine speeds 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 accomplished in one engine cycle divided by the engine's scavenging volume, i.e., engine torque normalized by engine displacement. The term "brake" refers to the actual torque / power available at the engine flywheel, as measured by a dynamometer. BMEP is therefore a measure of the engine's useful power output.

[0039] In certain embodiments, the engine is operated at a speed of about 500 rpm to about 3000 rpm, about 800 rpm to about 2800 rpm, or about 1000 rpm to about 2600 rpm. Additionally, the engine may be operated at a brake mean effective pressure of about 10 bar to about 30 bar, about 12 bar to about 30 bar, or about 12 bar to about 24 bar.

[0040] Although relatively infrequent, LSPI events can be catastrophic in nature. Therefore, it is desirable to significantly reduce or even completely eliminate LSPI events during normal or sustained operation of direct fuel injected engines.

[0041] In one embodiment, the method of the present invention provides at least a 10 percent, at least a 20 percent, at least a 30 percent, at least a 50 percent, at least a 60 percent, at least a 70 percent, at least a 80 percent, at least a 90 percent, or at least a 95 percent reduction in the number of LSPI events compared to an oil or lubricant composition that does not include one or more molybdenum compounds and one or more calcium-based detergents according to an embodiment.

[0042] Accordingly, one aspect of the present disclosure provides a method for reducing or preventing LSPI in a direct-injection, supercharged, spark-ignition internal combustion engine, the method 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 molybdenum, based on the total weight of the composition; and (iii) lubricating an engine with a used or aged lubricant composition comprising one or more calcium-based detergents in an amount providing the lubricant composition with at least about 1000 ppm of calcium, based on the total weight of the composition; A method is provided in which a used or aged lubricant composition lubricates an engine over the course of at least one oil change interval.

[0043] In one embodiment, (ii) the one or more molybdenum-containing compounds are in an amount providing the lubricant composition with at least about 850 ppm of molybdenum, based on the total weight of the composition, and (iii) the one or more calcium-based detergents are in an amount providing the lubricant composition with at least about 1800 ppm of calcium, based on the total weight of the composition.

[0044] In another embodiment, (ii) the one or more molybdenum-containing compounds are in an amount providing the lubricant composition with at least about 100 ppm to about 850 ppm of molybdenum, based on the total weight of the composition, and (iii) the one or more calcium-based detergents are in an amount providing the lubricant composition with at least about 1000 to about 1450 ppm of calcium, based on the total weight of the composition.

[0045] In certain embodiments, (iii) the one or more calcium-based detergents are present in an amount that causes the lubricant composition to contain 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.

[0046] 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.

[0047] In a particular embodiment, the engine is a downsized turbocharged engine.

[0048] Certain embodiments provide a method for maintaining the LSPI reduction capability of a used or aged lubricant composition in a direct-injection, supercharged, spark-ignition internal combustion engine, the method comprising lubricating the engine with a lubricant composition described herein.

[0049] In one embodiment, the disclosure provides a lubricating engine oil composition comprising a lubricant base stock (often referred to as a "base oil") as a major component and an LSPI additive disclosed herein (e.g., one or more molybdenum compounds and one or more calcium-based detergents) as a minor component, wherein the engine exhibits a greater than 50% LSPI reduction based on normalized LSPI counts per 100,000 engine cycles, at engine operating at 500 to 3,000 revolutions per minute and BMEP of 10 to 30 bar, compared to the LSPI performance achieved in the engine using a lubricant without the LSPI additive, wherein the LSPI additive comprises one or more molybdenum-containing compounds and one or more calcium-based detergents according to embodiments disclosed herein.

[0050] In one aspect, the present disclosure provides a lubricating engine oil composition for use in a downsized, supercharged engine comprising a lubricant base stock as a major component and an LSPI additive disclosed herein as a minor component, wherein the downsized engine has a volume ranging from 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 2, 3, 4, 5, or 6 cylinders.

[0051] In one aspect, the present disclosure provides for the use of the lubricant compositions disclosed herein for preventing or reducing LSPI in direct-injection, supercharged, spark-ignition internal combustion engines, particularly in aged or used lubricating engine oil compositions.

[0052] The methods disclosed herein may be used to prevent or reduce LSPI events in direct injection, supercharged, spark ignition internal combustion engines, particularly in aged or used lubricating oil compositions.

[0053] LSPI events are determined by monitoring peak cylinder pressure (PP) and cylinder fuel fraction burned (MFB). PP is typically reported in bars, and MFB is typically reported in crank angles. An LSPI event can be considered to have occurred if either or both criteria are met (i.e., if the PP and / or MFB thresholds are met and / or exceeded). The peak cylinder pressure threshold varies by 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 may be reported as the average number 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 with an MFB02 (2% MFB) greater than about 4.7 standard deviations and a peak pressure (PP) greater than 90 bar pressure (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.

[0054] It has been found that in engines prone to LSPI, the occurrence of LSPI can be reduced by lubricating such engines with the lubricant compositions disclosed herein, and more particularly, the incidence of LSPI is found to decrease sustainably as the lubricant composition ages.

[0055] The present disclosure further provides methods as described herein, wherein the engine is fueled with a liquid hydrocarbon fuel, a liquid non-hydrocarbon fuel, or a mixture thereof.

[0056] The present disclosure further provides a method as described herein, wherein the engine is fueled by natural gas, liquefied petroleum gas (LPG), compressed natural gas (CNG), or a mixture thereof.

[0057] 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-based 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.

[0058] Generally, the lubricant composition is for use with a lubricating engine oil composition. One or more oils of lubricating viscosity are included as major components of the lubricant composition.

[0059] Molybdenum Compounds Lubricant compositions according to embodiments include one or more molybdenum-containing compounds. The molybdenum-containing compounds can be any oil-soluble or oil-dispersible molybdenum-containing compound. The molybdenum compounds can be mononuclear, dinuclear, trinuclear, or tetranuclear.

[0060] Examples of oil-soluble or oil-dispersible organo-molybdenum compounds include molybdenum-amine complexes, molybdenum dithiocarbamates, molybdenum dithiophosphates, molybdenum dithiophosphinates, molybdenum xanthates, molybdenum thioxanthates, molybdenum carboxylates, molybdenum alkoxides, organo-molybdenum complexes, dispersed hydrated molybdenum compounds, and the like, and combinations thereof.

[0061] 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.

[0062] In one embodiment, the molybdenum-containing compounds are sulfurized oxymolybdenum dithiocarbamate, sulfurized oxymolybdenum dithiophosphate, amine-molybdenum complex compounds, oxymolybdenum diethylamide, and oxymolybdenum monoglyceride.

[0063] In one embodiment, the one or more molybdenum-containing compounds comprise 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 comprise an oxymolybdenum complex of a succinimide, particularly a sulfur-containing oxymolybdenum complex of a succinimide.

[0064] Molybdenum-amine complexes can generally be characterized as containing molybdenum or molybdenum / sulfur complexes of basic nitrogen compounds. The molybdenum compounds used to prepare the molybdenum-amine complexes are acidic molybdenum compounds (e.g., molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate, and other alkali metal molybdates, as well as other molybdenum salts such as MoOCl4, MoO2Br2, Mo2O3Cl6, molybdenum trioxide, or similar acidic molybdenum compounds). The basic nitrogen compounds should have a basic nitrogen content as measured by ASTM D-664 or D-2896. Typical examples of such compositions include succinimides, carboxylic acid amides, hydrocarbyl monoamines, hydrocarbon polyamines, Mannich bases, phosphonamides, (thio)phosphonamides, and combinations thereof. Examples of succinimides include succinimides with alkyl or alkenyl groups containing 8 or more carbon atoms (e.g., 8 to 400 carbon atoms). In certain embodiments, the succinimide has an alkyl or alkenyl group of 8 to 30, 12 to 30, or 8 to 18 carbon atoms.

[0065] The molybdenum / nitrogen-containing complex used herein is well known in the art, and is a complex of molybdic acid and oil-soluble basic nitrogen-containing compound.Generally, molybdenum / nitrogen-containing complex can be prepared by using an organic solvent containing a polar promoter during the complex formation step, and the preparation procedure of this complex is described in, for example, 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, Nos. 402,840, 6,962,896, 8,022,022, 8,022,023, 8,076,275, 8,183,189, 8,193,131, 8,193,132, 88,426,608, 8,476,460, and 8,980,806, and U.S. Patent Application Publication Nos. 2013 / 0261313, 2014 / 0179573, and 2014 / 0018269. As indicated in these references, the molybdenum / nitrogen-containing complexes can be further sulfurized.

[0066] Mono- and polysuccinimides that can be used to prepare the molybdenum amine complexes described herein are disclosed in numerous references and are well known in the art. The specific basic types of succinimides and related materials encompassed by the term "succinimide" are taught in U.S. Pat. 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 encompass many of the amide, imide, and amidine species that may be formed. However, the primary product is succinimide, and the term has generally been accepted to refer to the reaction product of an alkenyl-substituted succinic acid or anhydride with a nitrogen-containing compound. Preferred succinimides, due to their commercial availability, are those prepared from hydrocarbyl succinic anhydrides whose hydrocarbyl groups contain from about 24 to about 350 carbon atoms and ethyleneamines, particularly ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine. Particularly preferred are succinimides prepared from polyisobutenyl succinic anhydrides containing from 70 to 128 carbon atoms and tetraethylenepentamine or triethylenetetramine, or mixtures thereof. The term "succinimide" also includes cooligomers of hydrocarbyl succinic acids or anhydrides with polysecondary amines containing two or more secondary amino groups and at least one tertiary amino nitrogen. Typically, the average molecular weight of these compositions is 1,500 to 50,000. A typical compound would be prepared by reacting polyisobutenyl succinic anhydride with ethylenedipiperazine.

[0067] Succinimides having average molecular weights of 1000 or 1300 or 2300 and mixtures thereof are most preferred.

[0068] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum dithiophosphate (eg, a molybdenum dialkyldithiophosphate).

[0069] One class of molybdenum dithiophosphates useful herein is represented by formula (1): [ka] In the formula, R 1 and R 2 are independently C4~C 30 alkyl group, and x is an integer of 0 to 4. 1 and R 2 may be the same or different. Examples of commercially available molybdenum dialkyldithiophosphates include MOLYVAN® L (molybdenum di-(2-ethylhexyl) phosphorodithioate) available from RT Vanderbilt Company, or Sakura-lube 300® or Sakura-lube 310G® products available from Adeka.

[0070] In certain embodiments, R 1 and R 2 are independent, C4~C 24 In certain embodiments, R 1 and R 2 are independently C6 to C 18 The alkyl group is selected from the group consisting of:

[0071] 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.

[0072] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum dithiocarbamate (eg, a molybdenum dialkyldithiocarbamate).

[0073] One class of molybdenum dithiocarbamates (eg, dimeric molybdenum dithiocarbamates) useful herein is represented by formula (2): [ka] In the formula, R 3 and R 4 are independently C4~C 30 alkyl group, and x is an integer of 0 to 4. 3 and R 4 can be the same or different. The dimers can be symmetrical or asymmetrical. Examples of commercially available molybdenum dialkyldithiocarbamates include MOLYVAN® 807, MOLYVAN® 822, and MOLYVAN® 2000, available from RT Vanderbilt.

[0074] In certain embodiments, R 3 and R 4 are independent, C4~C 24 In certain embodiments, R 3 and R 4 are independently C6 to C 18 The alkyl group is selected from the group consisting of:

[0075] 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.

[0076] Another class of molybdenum dithiocarbamates useful herein (eg, trimeric molybdenum dithiocarbamates) is represented by formula (3): [ka] wherein y is an integer from 4 to 10, n is an integer from 1 to 4, each L is an alkyldithiocarbamate group, and each alkyl group is a C4 to C 30 The alkyl group is selected from the group consisting of:

[0077] 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.

[0078] In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4.

[0079] In certain embodiments, each L is an alkyldithiocarbamate group, where each alkyl group is a C-C 24 In certain embodiments, each L is an alkyldithiocarbamate group, where each alkyl group is selected from C to C 18 The alkyl group is selected from the group consisting of:

[0080] In certain embodiments, the molybdenum-containing compound is not a molybdenum dithiocarbamate.

[0081] In one embodiment, the one or more molybdenum-containing compounds include molybdenum dithiophosphinate.

[0082] In one embodiment, the one or more molybdenum-containing compounds comprise a molybdenum xanthate, for example, a molybdenum-alkyl xanthate such as molybdenum-ethyl xanthate.

[0083] In one embodiment, the one or more molybdenum-containing compounds include molybdenum thioxanthate.

[0084] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum carboxylate.

[0085] In one embodiment, the one or more molybdenum-containing compounds include a molybdenum alkoxide.

[0086] In one embodiment, the one or more molybdenum-containing compounds include an organo-molybdenum complex.

[0087] Two classes of organo-molybdenum complexes useful herein are represented by formulas (4a) and (4b) below.

[0088] [ka] [ka] In the formula, R 5 and R 6 are independent, C4~C 30 alkyl groups, and X 1 and X 2 are each independently O or NH. 5 and R 6 may be the same or different. X 1 and X 2 may be the same or different.

[0089] In certain embodiments, R 5 and R 6 are independent, C4~C 24 In certain embodiments, R 5 and R 6 are independently C6 to C 18 The alkyl group is selected from the group consisting of:

[0090] In certain embodiments, X 1 is O. In certain embodiments, X 1 is NH. In certain embodiments, X 2 is O. In certain embodiments, X 2 is NH.

[0091] Another class of organo-molybdenum complexes useful herein is represented by formula (5):

[0092] [ka] wherein y is an integer from 4 to 7, n is an integer from 1 to 4, each L is an independently selected ligand having an organic group with a sufficient number of carbon atoms to render the compound solubilizable or dispersible in oil, Q is selected from the group of neutral electron donor compounds such as water, amines, alcohols, phosphines, and ethers, and p is an integer from 0 to 5.

[0093] In one embodiment, y is 4. In one embodiment, y is 5. In one embodiment, y is 6. In one embodiment, y is 7.

[0094] In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4.

[0095] In certain embodiments, each L comprises at least 5 carbon atoms. In certain embodiments, the total number of carbon atoms included among all L groups is at least 21, at least 25, at least 30, or at least 35.

[0096] In certain embodiments, Q is selected from the group consisting of water, hydroxide, alkoxide, oxo, phosphine, phosphite, ammonia, amino, amide, halide, and combinations thereof.

[0097] 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.

[0098] In one embodiment, the one or more molybdenum-containing compounds comprise a dispersed hydrated molybdenum compound. Examples of dispersed hydrated molybdenum compounds include dispersed hydrated polymolybdates, dispersed hydrated alkali metal polymolybdates, and the like, and combinations thereof. Suitable dispersed hydrated polymolybdates include, for example, those disclosed in U.S. Patent No. 7,884,058.

[0099] Generally, the amount of molybdenum increases with the amount of calcium in the lubricant composition. In certain embodiments, the one or more molybdenum-containing compounds are present in an amount 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 molybdenum, based on the total weight of the composition.

[0100] In one embodiment, the metal amount of the molybdenum-containing compound in the lubricant composition is about 2000 ppm or less.

[0101] In certain embodiments, the one or more molybdenum-containing compounds are present in the lubricant composition in an amount ranging from about 100 ppm to about 2000 ppm, from about 150 ppm to about 2000 ppm, from about 166 ppm to about 2000 ppm, from about 200 ppm to about 2000 ppm, from about 250 ppm to about 2000 ppm, from about 270 ppm to about 2000 ppm, from about 300 ppm to about 2000 ppm, from about 350 ppm to about 2000 ppm, from about 400 ppm to about 2000 ppm, from about 450 ppm to about 2000 ppm, from about 500 ppm to about 2000 ppm, from about 550 ppm to about 2000 ppm, or from about 600 ppm to about 2000 ppm, based on the total weight of the composition. 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 molybdenum.

[0102] In certain embodiments, the one or more molybdenum-containing compounds are present in the lubricant composition in an amount of from about 100 ppm to about 1200 ppm, from about 150 ppm to about 1200 ppm, from about 200 ppm to about 1200 ppm, from about 250 ppm to about 1200 ppm, from about 270 ppm to about 1200 ppm, from about 300 ppm to about 1200 ppm, from about 350 ppm to about 1200 ppm, from about 400 ppm to about 1200 ppm, from about 400 ppm to about 1200 ppm, or from about 400 ppm to about 1200 ppm, based on the total weight of the composition. The amount is an amount that provides 50 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.

[0103] In certain embodiments, the one or more molybdenum-containing compounds are in an amount to provide the lubricant composition with from about 100 ppm to about 850 ppm, from about 150 ppm to about 850 ppm, from about 200 ppm to about 850 ppm, from about 250 ppm to about 850 ppm, from about 270 ppm to about 850 ppm, from about 300 ppm to about 850 ppm, from about 350 ppm to about 850 ppm, from about 400 ppm to about 850 ppm, from about 450 ppm to about 850 ppm, from about 500 ppm to about 850 ppm, from about 550 ppm to about 850 ppm, from about 600 ppm to about 850 ppm, from about 650 ppm to about 850 ppm, or from about 700 ppm to about 850 ppm of molybdenum, based on the total weight of the composition.

[0104] In certain embodiments, the one or more molybdenum-containing compounds are in an amount to provide the lubricant composition with from about 100 ppm to about 800 ppm, from about 150 ppm to about 800 ppm, from about 166 ppm to about 800 ppm, from about 200 ppm to about 800 ppm, from about 250 ppm to about 800 ppm, from about 270 ppm to about 800 ppm, from about 300 ppm to about 800 ppm, from about 350 ppm to about 800 ppm, from about 400 ppm to about 800 ppm, from about 450 ppm to about 800 ppm, from about 500 ppm to about 800 ppm, from about 550 ppm to about 800 ppm, from about 600 ppm to about 800 ppm, from about 650 ppm to about 800 ppm, or from about 700 ppm to about 800 ppm of molybdenum, based on the total weight of the composition.

[0105] In certain embodiments, the one or more molybdenum-containing compounds are in an amount to provide the lubricant composition with from about 100 ppm to about 400 ppm, from about 150 ppm to about 400 ppm, from about 166 ppm to about 400 ppm, from about 200 ppm to about 400 ppm, from about 250 ppm to about 400 ppm, from about 270 ppm to about 400 ppm, or from about 300 ppm to about 400 ppm of molybdenum, based on the total weight of the composition.

[0106] In certain embodiments, the one or more molybdenum-containing compounds are in an amount to provide the lubricant composition with from about 800 ppm to about 2000 ppm, from about 850 ppm to about 2000 ppm, from about 900 ppm to about 2000 ppm, from about 950 ppm to about 2000 ppm, from about 1000 ppm to about 2000 ppm, from about 1100 ppm to about 2000 ppm, from about 1200 ppm to about 2000 ppm, or from about 1300 ppm to about 2000 ppm of molybdenum, based on the total weight of the composition.

[0107] In certain embodiments, the one or more molybdenum-containing compounds are present in the lubricant composition in an amount that provides a ratio of ppm molybdenum to ppm calcium 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, based on the total weight of the composition.

[0108] 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 one or more molybdenum-containing compounds are present in the lubricant composition in a ratio of ppm molybdenum to ppm calcium ranging from about 1:2 to about 1:3, from about 1:2 to about 1:4, from about 1:2 to about 1:5, from about 1:2 to about 1:6, from about 1:2 to about 1:7, from about 1:2 to about 1:8, from about 1:2 to about 1:9, from about 1:2 to about 1:10, from about 1:3 to about 1:4, from about 1:3 to about 1:5, from about 1:3 to about 1:6, from about 1:3 to about 1:7, from about 1:3 to about 1:8, from about 1:3 to about 1:9, or from about 1:3 to about 1: The amount is about 1:10, about 1:4 to about 1:5, about 1:4 to about 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.

[0109] In certain embodiments, the one or more molybdenum-containing compounds are in an amount providing the lubricant composition with at least about 850 ppm of molybdenum, based on the total weight of the composition, and the one or more calcium-based detergents are in an amount providing the lubricant composition with at least about 1800 ppm of calcium, based on the total weight of the composition.

[0110] In certain embodiments, the one or more molybdenum-containing compounds are in an amount to provide the lubricant composition with from about 100 ppm to about 850 ppm of molybdenum, based on the total weight of the composition, and (iii) the one or more calcium-based detergents are in an amount to provide the lubricant composition with from about 1000 to about 1450 ppm of calcium, based on the total weight of the composition.

[0111] Calcium-based detergent Calcium-based detergents for use in the lubricant compositions of this disclosure include, but are not limited to, sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates, naphthenates, and other carboxylates of calcium, etc. In certain embodiments, the calcium-based detergents are neutral and / or overbased.

[0112] In certain embodiments, the one or more calcium-based detergents comprise or consist essentially of calcium sulfonate. In certain embodiments, the one or more calcium-based detergents comprise or consist essentially of calcium phenate. In certain embodiments, the one or more calcium-based detergents comprise or consist essentially of sulfurized calcium phenate. In certain embodiments, the one or more calcium-based detergents comprise or consist essentially of calcium thiophosphonate. In certain embodiments, the one or more calcium-based detergents comprise or consist essentially of calcium salicylate. In certain embodiments, the one or more calcium-based detergents comprise or consist essentially of calcium naphthenate. In certain embodiments, the one or more calcium-based detergents comprise or consist essentially of calcium carboxylate. In certain embodiments, the carboxylate is salicylate.

[0113] In certain embodiments, the lubricant composition comprises two or more types of calcium-based detergents.

[0114] In certain embodiments, the calcium-based detergent may be present in an amount to provide from about 600 ppm to about 3500 ppm, or from about 600 ppm to about 2400 ppm, from about 800 ppm to about 1800 ppm, from about 1200 ppm to about 1800 ppm, from about 1800 ppm to about 2400 ppm, or from about 1800 ppm to about 3500 ppm of calcium in the lubricant composition.

[0115] In certain embodiments, the calcium-based detergent may be present in an amount to provide the lubricant composition with 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.

[0116] Oil of lubricating viscosity The oil of lubricating viscosity used in the lubricant compositions of this disclosure, also referred to as base oil, is typically present in a major amount, e.g., greater than about 50 wt%, greater than about 60 wt%, greater than about 70 wt%, greater than about 80 wt%, or from about 60 to about 99.5 wt%, from about 70 to about 99.5 wt%, from about 80 to about 99.5 wt%, from about 85 to about 99.5 wt%, from about 60 to about 98 wt%, from about 70 to about 98 wt%, from about 80 to about 98 wt%, or from about 85 to about 98 wt%, based on the total weight of the composition. As used herein, the term "base oil" is understood to mean a base stock or blend of base stocks produced according to selected specifications (regardless of raw material supplier or location of manufacture). As used herein, a base oil may be any oil of lubricating viscosity now known or hereafter discovered that is used in formulating lubricant compositions for any application, such as engine oils, marine cylinder oils, and functional fluids such as hydraulic oils, gear oils, transmission oils, and the like.

[0117] As one skilled in the art will readily recognize, the viscosity of a base oil will depend on the application. Thus, the viscosity of base oils as used herein will typically range from about 2 to about 2000 centistokes (cSt) at 100° C. Generally, base oils used individually as engine oils will have a kinematic viscosity range of about 2 cSt to about 30 cSt at 100° C., preferably about 3 cSt to about 16 cSt, and most preferably about 4 cSt to about 12 cSt, and are selected or blended to produce a desired grade of engine oil (e.g., 0W, 0W-8, 0W-1), depending on the desired end use and additives in the finished oil. 2, 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.

[0118] Group I base oils generally refer to petroleum-derived lubricating base oils having less than 90 weight percent saturated hydrocarbons (as measured by ASTM D2007) and / or a total sulfur content greater than 300 ppm (as measured by ASTM D2622, ASTM D4294, ASTM D4297, or ASTM D3120), and a viscosity index (VI) greater than or equal to 80 but less than 120 (as measured by ASTM D2270).

[0119] Group II base oils generally refer to petroleum-derived lubricating base oils having a sulfur content of not more than 300 parts per million (ppm) by weight (as measured by ASTM D2622, ASTM D4294, ASTM D4927, or ASTM D3120), a saturated hydrocarbon content of not less than 90% by weight (as measured by ASTM D2007), and a viscosity index (VI) of 80 to 120 (as measured by ASTM D2270).

[0120] Group III base oil generally refers to petroleum-derived lubricating base oils that contain less than 300 ppm sulfur, greater than 90 wt. % saturated hydrocarbons, and have a VI value of 120 or greater.

[0121] Group IV base oils are polyalphaolefins (PAOs).

[0122] Group V base oils include all other base oils not included in Group I, II, III, or IV.

[0123] 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 III base oils.

[0124] The lubricant composition may contain minor amounts of other base oil components. For example, the lubricant composition may contain minor amounts of base oils derived from natural lubricants, synthetic lubricants, or mixtures thereof. Suitable base oils include base stocks obtained by the isomerization of synthetic wax and slack wax, as well as hydrocracked base stocks produced by hydrocracking (rather than solvent extraction) the aromatic and polar components of crude oil.

[0125] Suitable natural oils include mineral oil lubricants, such as liquid petroleum oils, solvent-treated or acid-treated mineral oil 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 oil), and the like.

[0126] Suitable synthetic lubricants include, but are not limited to, hydrocarbon oils and halo-substituted hydrocarbon oils (such as polymerized and copolymerized olefins, for example, polybutylene, polypropylene, propylene-isobutylene copolymers, chlorinated polybutylene, poly(1-hexene), poly(1-octene), poly(1-decene), and the like, and mixtures thereof); alkylbenzenes such as dodecylbenzene, tetradecylbenzene, dinonylbenzene, di(2-ethylhexyl)benzene; polyphenyls such as biphenyl, terphenyl, alkylated polyphenyls; alkylated diphenyl ethers; alkylated diphenyl sulfides; and derivatives, analogs, and homologs thereof.

[0127] Other synthetic lubricants include, but are not limited to, oils obtained by polymerizing olefins having less than 5 carbon atoms, such as ethylene, propylene, butylene, isobutene, pentene, and mixtures thereof. Methods for preparing such polymeric oils are well known to those skilled in the art.

[0128] Additional synthetic hydrocarbon oils include liquid polymers of alpha olefins having the appropriate viscosity. Particularly useful synthetic hydrocarbon oils include C6-C8 polymers such as 1-decene trimer. 12 It is a hydrogenated liquid oligomer of alpha olefins.

[0129] Another class of synthetic lubricants includes, but is not limited to, alkylene oxide polymers (i.e., homopolymers, interpolymers, and derivatives in which the terminal hydroxyl groups have been modified, such as by esterification or etherification). These oils are derived from the polymerization of ethylene oxide or propylene oxide, the alkyl and phenyl ethers of these polyoxyalkylene polymers (e.g., methyl polypropylene glycol ether of an average molecular weight of 1,000, diphenyl ether of polyethylene glycol of a molecular weight of 500 to 1,000, diethyl ether of polypropylene glycol of a molecular weight of 1,000 to 1,500, etc.), or their mono- and polycarboxylic acid esters, such as acetates, mixed C3 to C8 fatty acid esters, or C6 fatty acid esters of tetraethylene glycol.13 Typical examples include oils prepared by polymerization of oxo acid diesters.

[0130] Yet another class of synthetic lubricants includes the esters of dicarboxylic acids, such as phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acid, alkenyl malonic acid, and the like, with various alcohols, such as butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol, and the like. 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, dieicosyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, and a complex ester formed by reacting 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid.

[0131] Esters useful as synthetic oils include, but are not limited to, those prepared from carboxylic acids having from about 5 to about 12 carbon atoms and alcohols such as methanol, ethanol, polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and the like.

[0132] Silicon-based oils, such as polyalkyl, polyaryl, polyalkoxy, or polyaryloxy siloxane oils and silicate oils, represent another useful class of synthetic lubricants. Specific examples include, but are not limited to, tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate, tetra-(4-methylhexyl) silicate, tetra-(p-tert-butylphenyl) silicate, hexyl-(4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxane, and poly(methylphenyl)siloxane. Still other useful synthetic lubricants include, but are not limited to, liquid esters of phosphorus-containing acids, such as tricresyl phosphate, trioctyl phosphate, and the diethyl ester of decane phosphonic acid, as well as tetrahydrofuran polymers.

[0133] Lubricants can be derived from unrefined, refined, and rerefined oils (either natural oils, synthetic oils, or mixtures of two or more of any of the types disclosed above). Unrefined oils are those obtained directly from natural or synthetic sources (e.g., coal, shale, tar sands bitumen) without further purification or processing. Examples of unrefined oils include, but are not limited to, shale oil obtained directly from a retorting process, petroleum oil obtained directly from distillation, or ester oil obtained directly from an esterification process, all of which are used without further processing. Refined oils are similar to unrefined oils except they have been further treated in one or more purification steps to improve one or more properties. These purification techniques are known to those skilled in the art and include, for example, solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, hydrotreating, dewaxing, etc. Rerefined oils are obtained by treating used oils in processes similar to those used to obtain refined oils. Such rerefined oils, also known as reclaimed or reprocessed oils, are often further processed by techniques aimed at removing spent additives and oil breakdown products.

[0134] Lubricant base stocks derived from the hydroisomerization of wax may also be used, either alone or in combination with the aforementioned natural and / or synthetic base stocks. Such wax isomerate oils are produced by the hydroisomerization of natural or synthetic waxes or mixtures thereof over a hydroisomerization catalyst.

[0135] Natural waxes are typically slack waxes recovered by solvent dewaxing of mineral oils, while synthetic waxes are typically waxes produced by the Fischer-Tropsch process.

[0136] Other useful fluids of lubricating viscosity include unconventional or unconventional base stocks that are preferably catalytically processed or synthetically produced to provide high performance lubricating properties.

[0137] Lubricant Additives In general, the lubricant compositions of the present disclosure may contain additional lubricating additives. The lubricant compositions may further contain other conventional additives, such as those capable of imparting or improving any desirable properties of the lubricant composition in which the additive is dispersed or dissolved. Any additive known to those skilled in the art may be used in the lubricant compositions disclosed herein. Some suitable additives are described in 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), both of which are incorporated herein by reference. For example, the lubricant compositions can be blended with antioxidants, antiwear agents, metal detergents, rust inhibitors, dehaze removers, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoam agents, 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 similar compounds thereof, can be used to prepare the lubricant compositions of the present disclosure by conventional blending procedures.

[0138] In addition to calcium-based detergents, the lubricant compositions of the present disclosure may contain one or more non-calcium-based detergents, such as other metal-containing or ash-forming detergents. Metal-containing or ash-forming detergents function both 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 and a long hydrophobic tail. The polar head comprises a metal salt of an acidic organic compound. The salt may contain a near-stoichiometric amount of metal, in which case it is typically referred to as a normal or neutral salt. Large amounts of metal bases may be incorporated by reacting excess metal compounds (e.g., oxides or hydroxides) with acid gases (e.g., carbon dioxide).

[0139] Detergents that can be used include oil-soluble neutral and overbased sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates, naphthenates, and other oil-soluble carboxylates of metals, especially alkali metals or alkaline earth metals, such as barium, sodium, potassium, lithium, magnesium.

[0140] In one embodiment, the lubricant composition includes one or more magnesium-based detergents. In one embodiment, the magnesium-based detergent(s) may be added in an amount sufficient to provide the lubricant composition with about 100 to about 1000 ppm magnesium metal, or about 100 to about 600 ppm, or about 100 to about 500 ppm, or about 200 to about 500 ppm magnesium metal. In certain embodiments, the lubricant composition does not contain any magnesium-based detergents or magnesium-containing compounds.

[0141] In one embodiment, the lubricant composition includes one or more lithium-based detergents. In one embodiment, the lithium-based detergent(s) can be added in an amount sufficient to provide the lubricant composition with from 0 to about 2400 ppm lithium metal, from 0 to about 2200 ppm lithium metal, from 100 to about 2000 ppm lithium metal, from 200 to about 1800 ppm lithium metal, or from about 100 to about 1800 ppm, or from about 200 to about 1500 ppm, or from about 300 to about 1400 ppm, or from about 400 to about 1400 ppm lithium metal.

[0142] In one embodiment, the lubricant composition includes one or more sodium-based detergents. In one embodiment, the sodium-based detergent(s) can be added in an amount sufficient to provide the lubricant composition with from 0 to about 2400 ppm sodium metal, from 0 to about 2200 ppm sodium metal, from 100 to about 2000 ppm sodium metal, from 200 to about 1800 ppm sodium metal, or from about 100 to about 1800 ppm, or from about 200 to about 1500 ppm, or from about 300 to about 1400 ppm, or from about 400 to about 1400 ppm sodium metal.

[0143] In one embodiment, the lubricant composition includes one or more potassium-based detergents. In one embodiment, the potassium-based detergent(s) can be added in an amount sufficient to provide the lubricant composition with from 0 to about 2400 ppm potassium metal, from 0 to about 2200 ppm potassium metal, from 100 to about 2000 ppm potassium metal, from 200 to about 1800 ppm potassium metal, or from about 100 to about 1800 ppm, or from about 200 to about 1500 ppm, or from about 300 to about 1400 ppm, or from about 400 to about 1400 ppm potassium metal.

[0144] The lubricant composition of the present invention can include one or more antiwear agents capable of reducing friction and excessive wear. Any antiwear agent known to those skilled in the art can be used in the lubricant composition. Non-limiting examples of suitable antiwear agents include zinc dithiophosphates, metal (e.g., Pb, Sb, Mo, etc.) salts of dithiophosphates, metal (e.g., Zn, Pb, Sb, Mo, etc.) salts of dithiocarbamates, metal (e.g., Zn, Pb, Sb, etc.) salts of fatty acids, boron compounds, phosphate esters, phosphites, amine salts of phosphate esters or thiophosphate esters, reaction products of dicyclopentadiene and thiophosphoric acid, and combinations thereof. The amount of antiwear agent can vary from about 0.01 wt % to about 5 wt %, from about 0.05 wt % to about 3 wt %, or from about 0.1 wt % to about 1 wt %, based on the total weight of the lubricant composition.

[0145] In certain embodiments, the antiwear agent is or includes a metal dihydrocarbyl dithiophosphate, such as a zinc dialkyldithiophosphate compound. The metal of the metal dihydrocarbyl dithiophosphate can be an alkali or 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 metal dihydrocarbyl dithiophosphate 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 chain.

[0146] The amount of metal dihydrocarbyl dithiophosphate, including zinc dialkyl dithiophosphate, in the lubricant compositions disclosed herein is measured by its phosphorus content. In some embodiments, the lubricant compositions disclosed herein have a phosphorus content of from about 0.01 wt % to about 0.14 wt %, based on the total weight of the lubricant composition.

[0147] The lubricant composition of the present invention can contain one or more friction modifiers that can reduce friction between moving parts. Any friction modifier known to those skilled in the art can be used in the lubricant composition. Non-limiting examples of suitable friction modifiers include aliphatic carboxylic acids; derivatives of aliphatic carboxylic acids (e.g., alcohols, esters, borated esters, amides, and metal salts); 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, and metal salts); mono-, di-, or tri-alkyl-substituted amines; mono- or di-alkyl-substituted amides, and combinations thereof. Examples of friction modifiers in some embodiments include alkoxylated fatty amines; boronated fatty epoxides; fatty phosphites, fatty epoxides, fatty amines, boronated alkoxylated fatty amines, metal salts of fatty acids, fatty acid amides, glycerol esters, boronated glycerol esters; and aliphatic imidazolines as disclosed in U.S. Pat. No. 6,372,696, the contents of which are incorporated herein by reference; C4-C6 75 , or C6~C 24 , or C6~C 20 and mixtures thereof. The amount of friction modifier may vary from about 0.01% to about 10% by weight, from about 0.05% to about 5% by weight, or from about 0.1% to about 3% by weight, based on the total weight of the lubricant composition.

[0148] The lubricant composition of the present invention may contain an organic antioxidant in an amount of 0.01 to 5 wt %, preferably 0.1 to 3 wt %. The antioxidant may be a hindered phenol antioxidant or a diarylamine antioxidant. Diarylamine antioxidants are advantageous in that they provide a base number derived from nitrogen atoms. Hindered phenol antioxidants are advantageous in that they do not generate NOx gases.

[0149] Examples of hindered phenol antioxidants include 2,6-di-t-butyl-p-cresol, 4,4'-methylenebis(2,6-di-t-butylphenol), 4,4'-methylenebis(6-t-butyl-o-cresol), 4,4'-isopropylidenebis(2,6-di-t-butylphenol), 4,4'-bis(2,6-di-t-butylphenol), 2,2'-methylenebis(4-methyl-6-t-butylphenol), 4,4'-thiobis(2-methyl-6-t-butylphenol), phenol), 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, and octyl 3-(3,54-butyl-4-hydroxy-3-methylphenyl)propionate, as well as commercially available products such as, but not limited to, Irganox L135® (BASF), Naugalube 531® (Chemtura), and Ethanox 376® (SI Group).

[0150] Examples of diarylamine antioxidants include alkyldiphenylamines having a mixture of alkyl groups of 4 to 9 carbon atoms, p,p'-dioctyldiphenylamine, phenyl-naphthylamine, phenyl-naphthylamine, alkylated naphthylamine, and alkylated phenyl-naphthylamine.

[0151] The hindered phenol antioxidants and diarylamine antioxidants can be used alone or in combination. If desired, other oil-soluble antioxidants can be used in combination with the above antioxidant(s).

[0152] In certain embodiments, the lubricant composition comprises a sulfur-containing oxymolybdenum complex of succinimide as one of the one or more molybdenum-containing compounds, and an additive selected from a phenolic antioxidant or an aminic antioxidant.

[0153] In preparing lubricant formulations, it is common practice to incorporate additives in the form of 10 to 80% by weight of active ingredient concentrates in hydrocarbon oils (e.g., mineral oil-based lubricants) or other suitable solvents.

[0154] Typically, these concentrates can be diluted with 3 to 100 (e.g., 5 to 40) parts by weight of lubricant per part by weight of additive package to form a finished lubricant (e.g., crankcase motor oil). Of course, the purpose of the concentrate is to make handling of the various materials less difficult and awkward and to facilitate dissolution or dispersion in the final blend.

[0155] Typically, the sulfur level in the lubricant composition of the present invention is about 0.7 wt.% or less, e.g., about 0.01 wt.% to about 0.70 wt.%, 0.01 wt.% to about 0.6 wt.%, 0.01 wt.% to about 0.5 wt.%, 0.01 wt.% to about 0.4 wt.%, 0.01 wt.% to about 0.3 wt.%, 0.01 wt.% to about 0.2 wt.%, or 0.01 wt.% to about 0.10 wt.% sulfur, based on the total weight of the lubricant composition. In one embodiment, the sulfur level in the lubricant composition of the present invention is about 0.60 wt.% or less, about 0.50 wt.% or less, about 0.40 wt.% or less, about 0.30 wt.% or less, about 0.20 wt.% or less, or about 0.10 wt.% or less, based on the total weight of the lubricant composition.

[0156] In one embodiment, the level of phosphorus in the lubricant composition of the present invention is about 0.12 wt. % or less, e.g., from about 0.01 wt. % to about 0.12 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 about 0.11 wt. % or less, e.g., from about 0.01 wt. % to about 0.11 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 about 0.10 wt. % or less, e.g., from about 0.01 wt. % to about 0.10 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 about 0.09 wt. % or less, e.g., from about 0.01 wt. % to about 0.09 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 about 0.08 wt.% or less, e.g., from 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 about 0.07 wt.% or less, e.g., 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 about 0.05 wt.% or less, e.g., from about 0.01 wt.% to about 0.05 wt.% based on the total weight of the lubricant composition.

[0157] In one embodiment, the lubricant compositions of this invention produce sulfated ash levels of about 1.60 wt. % or less as determined by ASTM D874, e.g., about 0.10 to about 1.60 wt. % sulfated ash as determined by ASTM D874. In one embodiment, the lubricant compositions of this invention produce sulfated ash levels of about 1.00 wt. % or less as determined by ASTM D874, e.g., about 0.10 to about 1.00 wt. % sulfated ash as determined by ASTM D874. In one embodiment, the lubricant compositions of this invention produce sulfated ash levels of about 0.80 wt. % or less as determined by ASTM D874, e.g., about 0.10 to about 0.80 wt. % sulfated ash as determined by ASTM D874. In one embodiment, the lubricant compositions of this invention produce sulfated ash levels of less than or equal to about 0.60 wt. % as determined by ASTM D874, such as levels of from about 0.10 to about 0.60 wt. % sulfated ash as determined by ASTM D874.

[0158] 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).

[0159] Process for preparing lubricant compositions The lubricant compositions disclosed herein can be prepared by any method known to those skilled in the art for manufacturing lubricants. In some embodiments, the base oil can be blended or mixed with one or more molybdenum-containing compounds and one or more calcium-based detergents described herein. Optionally, one or more additional additives can be mixed or blended. The additional additives include commonly known lubricant additives, such as antiwear agents, antifoam agents, friction modifiers, antifoam agents, pour point depressants, viscosity index improvers, such as polymeric alkyl methacrylates, olefin copolymers, such as ethylene-propylene copolymers or styrene-diene copolymers, and the like, and mixtures thereof.

[0160] The one or more molybdenum-containing compounds and the one or more calcium-based 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-based detergents and optional additives are blended or mixed separately in one or more additions, and the additions may be in any order. In other embodiments, the one or more molybdenum-containing compounds and the one or more calcium-based detergents and additives are blended or mixed simultaneously, optionally in the form of an additive concentrate. In some embodiments, solubilization of the one or more molybdenum-containing compounds, the one or more calcium-based detergents, or optional solid additives in the base oil may be promoted by heating the mixture to a temperature of from about 25°C to about 200°C, from about 50°C to about 150°C, or from about 75°C to about 125°C.

[0161] Any mixing or dispersing device known to those skilled in the art may be used to blend, mix, or solubilize the ingredients. Blending, stirring, or solubilization may be carried out using a blender, agitator, disperser, mixer (e.g., planetary mixer and double planetary mixer), homogenizer (e.g., Gaulin homogenizer and Rannie homogenizer), grinder (e.g., colloid mill, ball mill, and sand mill), or any other mixing or dispersing device known in the art.

[0162] Application of the lubricant composition The lubricant compositions disclosed herein may be suitable for use as motor oils (i.e., engine oils or crankcase oils) for spark-ignition internal combustion engines, particularly direct-injection, supercharged engines prone to low-speed preignition.

[0163] The following examples are provided to illustrate embodiments of the present invention and are not intended to limit the invention to the specific embodiments shown. Unless otherwise indicated, all parts and percentages are by weight. All numerical values ​​are approximate. When numerical ranges are given, it should be understood that embodiments outside the stated ranges may still fall within the scope of the invention. The specific details described in each example should not be construed as necessary features of the invention. [Example]

[0164] The following examples are for illustrative purposes only and do not limit the scope of the present invention in any way.

[0165] Examples 1-4. Illustrative and Comparative Lubricant Compositions The exemplary and comparative lubricant composition formulations contained the following: Group II or Group III base oils, a mixture of calcium-based detergents in an amount to provide from about 1197 to about 2000 ppm of calcium to the lubricant composition; one or more molybdenum compounds selected from 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; a mixture of primary and secondary dialkyl zinc dithiophosphates in an amount to provide the lubricant composition with about 757 to about 890 ppm of zinc; a mixture of polyisobutenyl succinimide dispersants (borated and post-treated with ethylene carbonate); antifoaming agents, and Alkylated diphenylamine antioxidant.

[0166] Example 1 and Comparative Example 1 contained salicylate, phenate, and calcium sulfonate detergents as calcium sources, and molybdenum dithiocarbamate as molybdenum source.

[0167] Examples 2 to 4 and Comparative Example 2 contained phenate and calcium sulfonate detergents as calcium sources, and molybdenum-amine complexes as molybdenum sources.

[0168] Certain lubricant compositions also contained a boronated organic friction modifier and / or an olefin copolymer or poly(methyl acrylate) viscosity index improver. The friction modifier was not a Mo-containing compound. Example 1 and Comparative Example 1 contained a poly(methyl acrylate) viscosity index improver.

[0169] Certain lubricant compositions also included one or more magnesium-based detergents in an amount to provide from about 436 to about 473 magnesium to the composition.

[0170] The lubricant compositions were blended to form oils of viscosity grade 0W-20 (Example 1 and Comparative Example 1) or 0W-40 (Examples 2-4 and Comparative Example 2).

[0171] The amounts of each component of the exemplary and comparative lubricant compositions, in addition to the base oil, are shown in Table 1.

[0172] [Table 1] Example 5. Conditions for oil deterioration over time The lubricant compositions were aged according to the operating parameters summarized in Table 2. The aging process was a steady-state process carried out for a total of 72 hours. The resulting oil aged equivalent to an oil that had been driven approximately 5,000 miles under normal operating conditions.

[0173] [Table 2] Example 6. LSPI Testing of Aged Oils Containing Exemplary or Comparative Lubricant Compositions LSPI events were measured in a Ford 2.0L Ecoboost engine, which is a turbocharged gasoline direct injection (GDI) engine.

[0174] The Ford Ecoboost engine is run in four replicates of approximately four hours. The engine is run at a sump temperature of 95°C, 1750 rpm, and 1.7 MPa brake mean effective pressure (BMEP). At each stage, the engine is run through 175,000 combustion cycles and LSPI events are counted.

[0175] LSPI events are determined by monitoring peak cylinder pressure (PP) and cylinder fuel fraction burned (MFB). An LSPI event can be considered to have occurred if either or both criteria are met. The peak cylinder pressure threshold varies by 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 angles). LSPI events may be reported as the average number of events per test, events per 100,000 combustion cycles, events per cycle, and / or combustion cycles per event. Test results are shown in Table 3.

[0176] [Table 3]

[0177] The Ford used oil LSPI results for Example 1 versus Comparative Example 1 show that at high levels of calcium (2000 ppm), increasing the amount of molybdenum reduces the average number of LSPI events from 7.75 to 3.75. Additionally, a comparison of Examples 3 and 4 also shows that increasing the amount of molybdenum reduces the average number of LSPI events.

Claims

1. 1. A method for reducing or preventing low speed preignition (LSPI) in a direct injection, supercharged, spark ignition internal combustion engine, the method 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) lubricating the engine with the used or aged lubricant composition, the used or aged lubricant composition comprising one or more calcium-based 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, wherein the used or aged lubricant composition lubricates the engine over the course of at least one oil change interval.

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

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

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

5. 2. 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. 10. 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. 7. The method of claim 6, wherein the molybdenum-amine complex is a molybdenum succinimide complex.

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

9. 10. 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. 10. The method of claim 1, wherein the direct injection, supercharged, spark ignition internal combustion engine is operated under load at a brake mean effective pressure (BMEP) of about 12 to about 30 bar.

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

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

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

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

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

16. 10. The method of claim 1, wherein the at least one oil change interval is at least 3000 miles.

17. 10. The method of claim 1, wherein the at least one oil change interval is at least 5000 miles.

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