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The operating conditions of a typical motorcycle are considerably different than those of a typical passenger car and thus require an oil capable of handling the unique demands. One primary difference, wet clutch lubrication, is already addressed by the current JASO four-stroke motorcycle engine oil specification (JASO T 903:2011). Another challenge for the oil is gear box lubrication, which may be addressed in part with the addition of a gear protection test in a future revision to the JASO specification. A third major difference between a motorcycle oil and passenger car oil is the more severe conditions an oil is subjected to within a motorcycle engine, due to higher temperatures, engine speeds and power densities. Scooters, utilizing a transmission not lubricated by the crankcase oil, also place higher demands on an engine oil, once again due to higher temperatures, engine speeds and power densities.

Throughout the evolution of the automobile, passenger car motor oils have been developed to address issues of wear, corrosion, deposit formation, friction, and viscosity stability. As a result, the internal combustion engines are now developed with the expectation that the lubricants to be used in them will deliver certain performance attributes. Metallurgies, clearances, and built-in stresses are all chosen with certain expectations from the lubricant. A family of chemicals that has been universally used in formulating passenger car motor oils is zinc dithiophosphates (ZDPs). ZDPs are extremely effective at protecting highly stressed valve train components against wear failure, especially in engine designs with a sliding contact between cams and followers. While ZDPs' benefits on wear control are universally accepted, ZDPs have been identified as the source of phosphorus, which deactivates noble metal aftertreatment systems.

The world is firmly focused on reducing energy consumption and on increasingly stringent regulations on CO2 emissions. Examples of regulatory changes include the new United States Environmental Protection Agency's (U.S. EPA) fuel economy test procedures which were required beginning with the 2008 model year for vehicles sold in the US market. These test procedures include testing at higher speeds, more aggressive acceleration and deceleration, and hot-weather and cold-temperature testing. These revised procedures are intended to provide an estimate that more accurately reflects what consumers will experience under real world driving conditions. The U.S.

With the continued growth of the sport utility vehicle (SUV) market in North America in recent years more emphasis has been placed on fluid performance in these vehicles. In addition to fuel economy the key performance area sought by original equipment manufacturers (OEMs) in general has been temperature reduction in the axle. This is being driven by warranty claims that show that one of the causes of axle failure in these type vehicles is related to overheating. The overheating is, in turn, caused by high load situations, e.g., pulling a large trailer at or near the maximum rated load limit for the vehicle, especially when the vehicle or its main subcomponents are relatively new. The excessive temperature generally leads to premature failure of seals, bearings and gears. The choice of lubricant can have a significant effect on the peak and stabilized operating temperature under these extreme conditions.

Consumer demand for size, weight and horsepower has dictated a prominent role for sport utility vehicles and light trucks in the product lines of major North American automobile manufacturers. Inherently less efficient than passenger cars, these vehicles will be facing more stringent light duty CAFE (Corporate Average Fuel Economy) standards beginning in 2005 when mileage targets will be elevated to 21 mpg; this figure will be further increased to 22.2 mpg by 2007. In order to accommodate both public demand and CAFE requirements, vehicle manufacturers are seeking ways to improve fuel economy through design and material modifications as well as through improvements in lubrication. The axle lubricant may have an important impact on fuel economy, and axle lubricants can be tailored to deliver higher levels of operating efficiency over a wide range of conditions.

This paper outlines the history and background of the NLGI (formerly known as the National Lubricating Grease Institute) lubricating grease specifications, GC-LB classification of Automotive Service Greases as well as details on the development of new requirements for their High-Performance Multiuse (HPM) grease certification program. The performance of commercial lubricating grease formulations through NLGI's Certification Mark using the GC-LB Classification system and the recently introduced HPM grease certification program will be discussed. These certification programs have provided an internationally recognized specification for lubricating grease and automotive manufacturers, users and consumers since 1989. Although originally conceived as a specification for greases for the re-lubrication of automotive chassis and wheel bearings, GC-LB is today recognized as a mark of quality for a variety of different applications.

New technologies are being commercialized across the automotive industry to address demands for improved fuel economy, emissions reductions, and improved customer satisfaction. Push-belt continuously variable transmissions (b-CVTs) are beginning to command a significant percentage of the market now dominated by manual and conventional automatic transmissions. In addition, automobile manufacturers plan to introduce the first traction drive toroidal-CVTs to the market place within the next five years. A review of the relative benefits and limitations of each of these automatic transmissions exists in the literature. In this paper we consider how the performance requirements of each of these automatic transmission systems impact automatic transmission fluid technology. The physical characteristics and screen test performance of two commercial ATFs, a b-CVTF, and two traction fluids were examined.

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.

Modern high power density gasoline fueled engines place an ever-increasing demand on the engine lubricant. In this study, it is shown that advances in engine design to increase performance, improve fuel economy and lower emissions have outpaced the development of typical commercial engine lubricants. Advanced designed engines began to experience oil starvation as a result of a combination of driving cycles, oil quality and poor maintenance practices. The cause was traced to excessive increases in borderline pumping viscosity as measured by MRV TP-1 (ASTM D4684). Used oil analysis for MRV TP-1 showed viscosity greatly increased in excess of stay-in-grade requirements and in many cases the crankcase lubricant was solid at the temperature appropriate for its viscosity grade. However, at the same time CCS values were in grade or only slightly (1W grade) elevated.

Downsized gasoline engines, coupled with gasoline direct injection (GDI) and turbocharging, have provided an effective means to meet both emissions standards and customers’ drivability expectations. As a result, these engines have become more and more common in the passenger vehicle marketplace over the past 10 years. To maximize fuel economy, these engines are commonly calibrated to operate at low speeds and high engine loads – well into the traditional ‘knock-limited’ region. Advanced engine controls and GDI have effectively suppressed knock and allowed the engines to operate in this high efficiency region more often than was historically possible. Unfortunately, many of these downsized, boosted engines have experienced a different type of uncontrolled combustion. This combustion occurs when the engine is operating under high load and low speed conditions and has been named Low Speed Pre-Ignition (LSPI). LSPI has shown to be very damaging to engine hardware.

The continued development of more powerful aviation turbine engines has demanded greater thermal stability of the fuel as a high temperature heat sink. This in turn requires better definition of the thermal stability of jet fuels. Thermal stability refers to the deposit-forming tendency of the fuel. It is generally accepted that dissolved oxygen initiates the deposition process in freshly refined fuels. While there are many tests that are designed to measure or assess thermal stability, many of these either do not display sufficient differentiation between fuels of average stability (JP-8) and intermediate stability (JP-8+100, JP-TS), or require large test equipment, large volumes of fuels and/or are costly. This paper will discuss the use of three laboratory tests as “concept thermal stability prediction” tools with aviation fuels, including Jet A-1 or JP-8, under JP8+100 test conditions.

A measurable incidence of driver complaints about vehicle driveability has occurred in certain imported passenger cars. Critical engines are higher specific output, lean burn designs that are sensitive to deposits formed on intake valves. U.S. engines are trending toward similar” designs but have not yet been tuned as close to the lean limit of combustion. It is reasoned that the continuing trend toward more precise management of air fuel ratio results in engines much less tolerant of deposits throughout the fuel metering and induction system. Consequently, more effective additive systems to control induction system deposits have been developed. Discussed in this paper are the interrelationships of fuel composition and engine configurations. Results of these continuing studies are helping to define the more important fuel and additive parameters for deposit control in various engines.

Requirements to improve vehicle fuel economy continue to increase, spurred on by agreements such as the Kyoto Protocol. Lubricants can play a role in aiding fuel economy, as evidenced by the rise in the number of engine oil specifications that require fuel economy improvements. Part of this improvement is due to achieving suitable viscometric properties in the lubricant, but additional improvements can be made using friction modifier (FM) compounds. The use of FMs in lubricants is not new, with traditional approaches being oleochemical-based derivatives such as glycerol mono-oleate and molybdenum-based compounds. However, to achieve even greater improvements, new new friction modifying compounds are needed to help deliver the full potential required from next generation lubricants. This work looks at the potential improvements available from new FM technology over and above the traditional FM compounds.

The Sequence IIIG is a newly developed 100 hour test used to evaluate the performance of crankcase engine oils in the areas of high temperature viscosity increase, wear, deposits, pumpability, and ring sticking for the North American GF-4 standard. Data from the ASTM Precision Matrix, completed in the spring of 2003, along with early reference data from the Lubricant Test Monitoring System (LTMS) showed unexpected test results for selected oils and indicated that percent viscosity increase and pumpability were highly correlated with oil consumption. This correlation led to an intensive study of the factors that influence oil consumption and an attempt to compensate for non-oil related oil consumption through a model based adjustment of the results. The study and scrutiny of the IIIG data has led to more uniform oil consumption in the test and improved test precision, and has eliminated the need for a correction equation based on non-oil related oil consumption.

The effects of lubricating oil on friction and engine-out emissions in a light-duty 2.2L compression ignition direct injection (CIDI) engine were investigated. A matrix of test oils varying in viscosity (SAE 5W-20 to 10W-40), friction modifier (FM) level and chemistry (MoDTC and organic FM), and basestock chemistry (mineral and synthetic) was investigated. Tests were run in an engine dynamometer according to a simulated, steady state FTP-75 procedure. Low viscosity oils and high levels of organic FM showed benefits in terms of fuel economy, but there were no significant effects observed with the oils with low MoDTC concentration on engine friction run in this program. No significant oil effects were observed on the gaseous emissions of the engine. PM emissions were analyzed for organic solubles and insolubles. The organic soluble fraction was further analyzed for the oil and fuel soluble portions.

Studies of selected automotive gear lubricants in heavy truck tandem axles and transmissions have revealed improvements in fuel economy associated with the viscosity of lubricants tested (grades 75W, 75W-90, and 80W-140). The testing included a heavy truck on-highway fleet test and test track operation. Standard laboratory gear tests on light viscosity monograde (SAE 75W) oils indicate that oils of this type may be deficient in EP protection. Combined observations show that there may be a critical balance between axle lubricant fuel economy benefits and axle durability in field service.

Significant reductions of particulate matter (PM) and nitrogen oxides (NOx) emissions from diesel engines have been realized through fueling with water-fuel emulsions. However, the physical and chemical in-cylinder mechanisms that affect these pollutant reductions are not well understood. To address this issue, laser-based and chemiluminescence imaging experiments were performed in an optically-accessible, heavy-duty diesel engine using both a standard diesel fuel (D2) and an emulsion of 20% water, by mass (W20). A laser-based Mie-scatter diagnostic was used to measure the liquid-phase fuel penetration and showed 40-70% greater maximum liquid lengths with W20 at the operating conditions tested. At some conditions with low charge temperature or density, the liquid phase fuel may impinge directly on in-cylinder surfaces, leading to increased PM, HC, and CO emissions because of poor mixing.

The engine-out emissions and fuel consumption rates for a modern, heavy-duty diesel engine were compared when fueling with a conventional diesel fuel and three water-blend-fuel emulsions. Four different fuels were studied: (1) a conventional diesel fuel, (2) PuriNOx,™ a water-fuel emulsion using the same conventional diesel fuel, but having 20% water by mass, and (3,4) two other formulations of the PuriNOx™ fuel that contained proprietary chemical additives intended to improve combustion efficiency and emissions characteristics. The emissions data were acquired with three different injection-timing strategies using the AVL 8-Mode steady-state test method in a Caterpillar 3176 engine, which had a calibration that met the 1998 nitrogen oxides (NOX) emissions standard.

Global original equipment manufacturers (OEMs) have requested lower viscosity automatic transmission fluid (ATF) for use in conventional and 6-speed automatic transmissions (AT) to meet growing demands for improved fuel economy. While lower-viscosity ATF may provide better fuel economy by reducing churning losses, other key performance attributes must be considered when formulating lower viscosity ATF(1,2). Gear and bearing performance can be key concerns with lower-viscosity ATFs due to reduced film thickness at the surfaces. Long-term anti-shudder performance is also needed to enable the aggressive use of controlled slip torque converter clutches that permit better fuel economy. And, friction characteristics need to be improved for higher clutch holding capacity and good clutch engagement performance. This paper covers the development of next-generation, low-viscosity ATF technology, which provides optimum fuel economy along with wear and friction durability.

Light trucks and sport utility vehicles (SUVs) have become extremely popular in the United States in recent years, but this shift to larger passenger vehicles has placed new demands upon the gear lubricant. The key challenge facing vehicle manufacturers in North America is meeting government-mandated fuel economy requirements while maintaining durability. Gear oils must provide long-term durability and operating temperature control in order to increase equipment life under severe conditions while maintaining fuel efficiency. This paper describes the development of a full-scale light duty axle test that simulates a variety of different driving conditions that can be used to measure temperature reduction properties of gear oil formulations. The work presented here outlines a test methodology that allows gear oil formulations to be compared with each other while accounting for axle changes due to wear and conditioning during testing.