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Increasingly stringent fuel economy and emissions regulations around the world have forced the further optimization of nearly all vehicle systems. Many technologies exist to improve fuel economy; however, only a smaller sub-set are commercially feasible due to the cost of implementation. One system that can provide a small but significant improvement in fuel economy is the lubrication system of an internal combustion engine. Benefits in fuel economy may be realized by the reduction of engine oil viscosity and the addition of friction modifying additives. In both cases, advanced engine oils allow for a reduction of engine friction. Because of differences in engine design and architecture, some engines respond more to changes in oil viscosity or friction modification than others. For example, an engine that is designed for an SAE 0W-16 oil may experience an increase in fuel economy if an SAE 0W-8 is used.

Fuel economy is not an absolute attribute, but is highly dependent on the method used to evaluate it. In this work, two test methods are used to evaluate the differences in fuel economy brought about by changes in engine oil viscosity grade and additive chemistry. The two test methods include a chassis dynamometer vehicle test and an engine dynamometer test. The vehicle testing was conducted using the Federal Test Procedure (FTP) testing protocol while the engine dynamometer test uses the proposed American Society for Testing and Materials (ASTM) Sequence VIE fuel economy improvement 1 (FEI1) testing methodology. In an effort to improve agreement between the two testing methods, the same model engine was used in both test methods, the General Motors (GM) 3.6 L V6 (used in the 2012 model year Chevrolet™ Malibu™ engine). Within the lubricant industry, this choice of engine is reinforced because it has been selected for use in the proposed Sequence VIE fuel economy test.

Chassis dynamometer tests are often used to determine vehicle fuel economy (FE). Since the entire vehicle is used, these methods are generally accepted to be more representative of ‘real-world’ conditions than engine dynamometer tests or small-scale bench tests. Unfortunately, evaluating vehicle fuel economy via this means introduces significant variability that can readily be mitigated with engine dynamometer and bench tests. Recently, improvements to controls and procedures have led to drastically improved test precision in chassis dynamometer testing. Described herein are chassis dynamometer results from five fully formulated engine oils (utilizing improved testing protocols on the Federal Test Procedure (FTP-75) and Highway Fuel Economy Test (HwFET) cycles) which not only show statistically significant FE changes across viscosity grades but also meaningful FE differentiation within a viscosity grade where additive systems have been modified.

Increasing pressure to deliver vehicle fuel efficiency without compromising engine durability places significant demands on engine lubricants. The antiwear capability of the formulation is extremely important as wear on engine parts can lead to engine inefficiency. The rapidly advancing and diversifying array of engine architectures creates ever more arduous conditions under which lubricant additives must perform. The evolution of engine design brings with it the propensity for a variety of wear mechanisms to occur. This paper reports research conducted to rapidly collect key information from which to begin to conceive the design of better screening technologies. An exploration of wear mechanisms using simple bench-top experiments was conducted using a variety of lubricants. A lab based oil-aging technique was used to attempt to create an oil sample with wear properties mimiking those of real engine drains.

The global commitment to reduce CO2 emissions drives the automotive industry to create ever more advanced chemical and engineering systems. Better vehicle fuel efficiency is demanded which forces the rapid evolution of the internal combustion engine and its system components. Advancing engine and emission system technology places increasingly complex demands on the lubricant. Additive system development is required to formulate products capable of surpassing these demands and enabling further reductions in greenhouse gas emissions. This paper reports a novel method of generating fundamental structure-performance knowledge with real-world meaning. Traditional antiwear molecule performance mechanisms are explored and compared with the next generation of surface active additive system (SAAS) formulated with only Nitrogen, Oxygen, Carbon and Hydrogen (NOCH).