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With government mandates, original equipment manufacturers are increasingly focusing on fuel economy and finding efficiency gains throughout the vehicle. Lubricant companies have been asked to design fluids that aid in this effort. Demonstrating real gains becomes complex given the intricacies of these systems and methods range from bench top screen tests to component test stands to full vehicle testing. This paper addresses the variation that was encountered when testing automatic transmission fluid efficiency within a full vehicle test. While it is well known that variability in testing conditions such as engine load or vehicle speed will lead to variability in results, the magnitude of their impact on average throughout the test cycle suggests that repeat testing may not be sufficient to guard against improper conclusions.

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.

Hybrid drivetrain hardware combines an electric motor and a transmission, gear box, or hydraulic unit. With many hybrid electric vehicle (HEV) hardware designs the transmission fluid is in contact with the electric motor. Some OEMs and tier suppliers have concerns about the electrical properties of automatic transmission fluids (ATFs). Lubrizol has conducted a fundamental research project to better understand the electrical conductivity of ATFs. In this paper, we will present conductivity data as a function of temperature for a range of commercially available ATFs. All fluids had conductivities ranging from 0.9 to 8x10-9 S/cm at 100 °C and can be considered insulators with the ability to dissipate static charge. Next we will deconstruct one ATF to show the relative impact of the various classes of lubricant additives. We find that more polar additives have a larger effect on conductivity on a normalized (per weight %) basis.

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).