Lubricant compositions for high efficiency engines

Abstract

The instant disclosure is directed to a method of lubricating a sump-lubricated, high efficiency, gasoline-fueled internal combustion engine. Said method involves supplying to the engine a lubricatingcomposition comprising an oil of lubricating viscosity, an anti-wear agent, an ashless antioxidant, a metal-containing detergent, an ashless polyolefin dispersant, and (f) a polymeric viscosity modifier. The disclosure further provides a method of operating a high efficiency sump-lubricated gasoline-fueled internal combustion engine while maintaining or improving at least one of durability, deposit control, oxidation control, fuel economy, and resistance to knock and stochastic pre-ignition.

Description

Background technique [0001] The disclosed technology relates to lubricants for internal combustion engines, specifically those lubricants for gasoline fueled engines. [0002] Modern engine designs are being developed to increase thermal efficiency without sacrificing performance or durability, and without increasing emissions of potentially harmful exhaust gases such as nitrogen oxides (NO x ), non-combustible hydrocarbons (HC) and carbon monoxide (CO). [0003] The challenge of increasing the thermal efficiency of an engine, and thus fuel efficiency, involves extracting more torque from the engine for a given displacement. Achieving this goal requires a combination of hardware design changes, optimization of engine operating parameters such as fuel-to-air ratio, and lubricant design. [0004] Brake mean effective pressure (BMEP) is a measure of engine output normalized to engine displacement. Improving the efficiency of gasoline fueled engines will require the engine to r...

AI Technical Summary

Problems solved by technology

[0003] The challenge of increasing the thermal efficiency of an engine, and therefore fuel efficiency, involves extracting more torque from said engine for a given displacement

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