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Motorcycle manufacturers have recognized that highly friction modified passenger car oils can be deleterious to clutch performance, leading to clutch slippage. To address this issue, a JASO specification for four-stroke motorcycle oils was developed in 1999, categorizing oils into high friction oils termed JASO MA and low friction oils termed JASO MB. The high friction oils were preferred for most motorcycles where the engine oil also lubricates the clutch and gears. New motorcycle transmission technologies have increased the number of dry clutch applications which has led to an increased demand for JASO MB oils to improve fuel efficiency. While JASO MB oils contain friction modifiers to improve initial fuel economy, the motorcycle specifications have not addressed the fuel economy durability of motorcycle oils.

A major drive to develop methanol-fueled vehicles began with the 1973 oil embargo. Early work with dedicated methanol-fueled vehicles demonstrated that lubricant choice influenced engine durability. The qualities desired were not defined by the gasoline engine oil classification system in place at the time. As a result oils were developed which optimized those properties deemed desirable for methanol fuel. The advent of fuel sensors made it possible to design a vehicle which can operate on gasoline or gasoline with varying levels of methanol without intervention by the operator. This created a need for a lubricant that can handle a diversity of methanol/gasoline mixtures as well as conventional gasoline. The paper reviews some of the lubricants that have been used in prototype methanol-capable vehicles and the improvement of these formulations to meet the latest gasoline engine performance criteria while maintaining satisfactory methanol performance.

Water-emulsified diesel fuel technology has been proven to reduce nitrogen oxides (NOx) and particulate matter (PM) simultaneously at relatively low cost compared to other pollution-reducing strategies. The value of this technology is that it requires absolutely no engine adjustments or modifications to reduce harmful emissions. Technologies that break the NOx -particulate trade-off are virtually non-existent, therefore understanding how the water contained in an emulsified fuel can reduce both NOx and PM simultaneously is critical. To understand this phenomenon, emulsified fuels with varying water levels (0 to 20%) were evaluated in a multi-cylinder marine engine using three different injection timings. This testing in an actual engine confirms that as the water level is increased the amount of NOx and PM are reduced without compromising engine performance.

A discriminating dynamometer-based test was developed for evaluating cold start and warmup engine performance based on in-cylinder pressure measurements. The dynamometer test offers advantages in time required, flexibility and reduced variability over the vehicle procedure on which it was based. A parametric study on fuel driveability index (DI), ethanol content and intake valve deposit (IVD) rating demonstrated that each of these parameters had a statistically significant impact on engine cold start performance. Simple numerical offsets to fitted models based on oxygen content of the fuel did not account for the difference in engine performance of hydrocarbon-only versus ethanol-containing fuels. The effect of IVD on engine performance did not appear to depend on the DI of the fuel. The benefits of cleaner valves are seen even in fuels of very low DI.

Requirements to reduce emissions and improve vehicle fuel economy continue to increase, spurred on by agreements such as the Kyoto Protocol. Lubricants can play a role in improving fuel economy, as evidenced by the rise in the number of engine oil specifications worldwide that require fuel economy improvements. A novel friction modifier technology has been developed to further improve vehicle fuel economy. The development of this novel friction modifier technology which contains only N,O,C,H was previously published along with the initial demonstration of performance in motorized Toyota engines. In order to validate this performance in fired engine tests, oil was evaluated in a Toyota Corolla Fielder with a 1500 cc gasoline engine. Testing was conducted in the Japanese 10-15 and JC08 modes, as well as the European EC mode, and the US FTP mode.

The use of a copper diesel fuel additive in an emission control system improves particulate oxidation. This expands the operability of available systems by reducing the particulate mass loading and related external energy consumption required during regeneration. Easier, more frequent regenerations improve overall engine/system efficiency and reduce thermal stress on filtration media. Procedures for optimizing additive use are presented. In addition, the results from a health study are reviewed.

The international Lubricant Standardization and Approval Committee (ILSAC) GF-2 specification requires Passenger Car Motor Oils to provide enhanced fuel economy in a modern low friction engine (ASTM Sequence VIA). In previous SAE publications the authors have studied the boundary lubrication regime and documented the impact of friction modifiers and antiwear additives on Sequence VIA fuel economy. This paper shifts the focus to the hydrodynamic lubrication regime and details fundamental studies of viscosity modifiers and base oils on fuel economy as measured by this low friction engine. The viscosity modifiers were found to have surprisingly little impact on this test, while moving to base oils of higher viscosity index improved fuel economy as might be theoretically expected. A study of formulating SAE 5W-30 motor oils with base oils of increasing viscosity index showed the optimum fuel economy was able to be obtained with a high viscosity index base stock.

The regenerative characteristics of a diesel particulate filter have been experimentally examined. The effect of particulate accumulation on system backpressure was of primary interest. To improve particulate regeneration, a copper compound was added to the fuel. The test results demonstrate that copper-containing fuel additives improve the regeneration characteristics of the filter, maintaining system backpressure at an acceptable level. Improved regeneration performance is expected to extend the operating range and life of the filter system. A model describing regeneration characteristics was developed to indicate the benefits of fuel copper concentration in controlling system backpressure.

The technology has been developed which will allow manufacturers to produce cars capable of running on methanol/gasoline blends with a methanol content up to 85% (i.e., M85). These cars will operate on varying methanol/gasoline ratios without any adjustments from the driver. The dual-fuel capability is attractive since vehicle use will not be handicapped by a restricted fuel distribution system. In addition, it provides the option of running on an environmentally “cleaner” fuel where it is available. The advent of fuel-flexible vehicles encourages the development of lubricants which will satisfy the demands of both fuels. The unique properties of methanol, however, increase the challenges of meeting the lubricant performance needs. Field and engine dynamometer testing have been aimed at understanding the response of key lubricant variables with M85. Short-trip, cold-weather conditions have been of particular concern.

A test was developed by the Cummins Engine Company to evaluate Diesel fuel quality and potential additive effects. This test utilizes a Cummins L10 Diesel engine with a PT fuel system and stepped plunger injectors. A modified CRC rating system is used to quantify deposit levels. This paper further investigates the L10 Injector Depositing Test and will focus on Diesel fuel and additive variables. In the original work, the bulk of the data was collected on an industry standard reference fuel, Cat 1-H, as opposed to commercially available Diesel fuels. Commercially available Diesel fuel varies in composition with regard to sulfur level, percent aromatics, final distillation end point, and cetane number. To evaluate these fuel properties and their possible effects on injector deposit formation, two test matrices were designed. The first experiment is a 12-run fractional factorial design with four factors: additive level, sulfur, aromatics, and 90 percent distillation point (T90).

A test method has been developed which provides for the rapid measurement of the scuffing performance of diesel fuel using the Ball-On-Cylinder Lubricity Evaluator (BOCLE). A test can be completed in less than one hour. Data has been generated indicating that the method achieves good discrimination between fuels of varying lubricity and correlates well with fuel performance as measured in pump tests.

The effects of gasoline composition, as represented in typical regular and premium unleaded gasolines and fuel additives, on Combustion Chamber Deposits (CCD) were investigated in BMW and Ford tests. In addition, the influences of engine lubricant oil and ethanol oxygenate on CCD were examined in Ford 2.3L engine dynamometer tests. Also, additive effects of packages based on mineral oil fluidizers versus synthetic fluidizers were studied in several different engines for CCD. Finally, a new method for evaluating the effect of fluidizers on valve sticking is introduced.

The proposed International Lubricant Standardization and Approval Committee (ILSAC) GF-2 specification requires Passenger Car Motor Oils to provide enhanced fuel economy in a modern low friction engine (Sequence VIA). This paper details fundamental studies of lubricant effects on fuel economy as measured by this low friction engine. Several conventional friction modifiers were tested with surprising results. One ester friction modifier, Ester B, which provides excellent fuel economy improvement in the Sequence VI, was found to be detrimental to the Sequence VIA. A second ester friction modifier, Ester A, performed as expected. Additionally, two molybdenum compounds, which are reported to provide excellent fuel economy in the Sequence VI, showed no fuel economy benefit in the Sequence VIA.

This paper presents the evaluation results from the EMA durability test on 25% high oleic sunflower oil/75% diesel fuel and 25% high oleic safflower oil/75% diesel fuel. The test results from both fuels were compared to the outcome for a standard diesel fuel. The fuels were compared based on the performance and emissions results including; power output, fuel consumption, CO, CO2, NO and HC and the carbon and lacquer residue formation on the internal parts of the engine. The results indicated no significant change in engine performance for the tested fuels, throughout the duration of the investigation. The carbon and lacquer residue formations were within a normal range for both fuels in comparison to the results from the fuel for standard diesel fuel.

The authors provide evidence indicating that oils meeting only the minimum requirements of API GL-5 do not always provide adequate gear protection, especially in severe duty applications. Increases in commercial vehicle power and loading have accentuated the need for oils of greater load carrying ability. A modified version of the standard L-37 test may help identify oils that possess superior durability and thermal characteristics. Future gear lubricants should provide improved fuel economy, increased manual transmission life; and frictional characteristics that allow noise free performance in limited slip differentials.

In order to assess the field needs of engine oils to be used in methanol-fueled vehicles, six oils were run in a fleet test over a ten-month period under short-trip service conditions. The results from the field test were compared with results with the six oils in the laboratory engine tests which have been used to predict field performance with methanol fuel. A lack of correlation between the field test and the laboratory engine tests suggests that the laboratory tests need revisions to better serve field needs.

Additives are an integral part of today's fuels. Together with carefully formulated base fuel composition, they contribute to efficiency, dependability and long life of gasoline and diesel engines. As a primer, this paper describes the range of chemical additives formulated for gasoline and diesel fuel and their effects. Specific functions and benefits of additives, typical use levels, and test methods for evaluation are discussed. Additive usage may be divided into three major categories: a) to satisfy desired levels of performance in engines, b) to insure delivery of uncontaminated, on-specification fuels to the end user and c) achieve necessary chemical/physical properties as manufactured by the refiner.

Multifunctional additives can compensate for lower quality diesel fuel. Performance and quality have been decreasing worldwide. This has resulted largely from increased use of heavier crude oils and more severe processing to achieve necessary fuel product mix. Fuel additives provide the refiner and marketer with an economic approach to restoring performance and quality. Additives can be formulated to solve many problems related to deposits and wear, which are major factors affecting engine power, economy, emissions and durability. They are of critical importance to the vehicle owner/ operator to maintain dependability and low operating cost. At the same time, the refiner benefits economically through the use of lower cost crudes, greater operational flexibility and ease of adjusting final fuel blends to meet specifications. Typical additive components include: detergent dispersants, inhibitors, stabilizers, cetane improvers, and flow improvers.

Additives are an integral part of today's fuels. Together with carefully formulated base fuel composition, they contribute to efficiency, dependability and long life of gasoline and diesel engines. As a primer, this paper describes the range of chemical additives formulated for gasoline and diesel fuel and their effects. Specific functions and benefits of additives, typical use levels, and test methods for evaluation are discussed. Additive usage may be divided into three major categories: a) to satisfy desired levels of performance in engines, b) to insure delivery of uncontaminated, on-specification fuels to the end user and c) achieve necessary chemical/physical properties as manufactured by the refiner.

In the first paper in this series (1)*, the extent of oil thickening for a given lubricant in the Mack T-7 engine test was found to be influenced by fuel composition. Based upon the knowledge that thickening is due to the accumulation and aggregation of soot in the oil, a set of experiments has been carried out to identify relationships between fuel chemistry and the oil thickening tendency of soot formed by fuel combustion. Three commercial diesel fuels were treated with chemical combustion aids and/or organic sulfur, and both short-duration and full-length tests were run in a Mack T-7 engine fitted with a filter designed to collect soot from the exhaust stream. A model describing the complex effects of fuel chemistry on the oil thickening process is proposed in which fuel sulfur content is shown to influence soot content of the lubricant after ISO hours of engine operation.