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Four 1998 Mitsubishi Carismas, two equipped with direct injection and two with port fuel injection engines, were tested in 20,100 km intervals to determine the effect of mileage accumulation cycle, engine type, fuel and lubricant on vehicle deposits and emissions, acceleration and driveability performance. The program showed that engine fuel system deposits, including specifically those on intake valves, combustion chambers and injectors are formed in higher amounts in the GDI engine than the PFI engine. The fuel additive used reduced injector deposits and combustion chamber deposits in the GDI, but had no significant effect on intake valve deposits, which are affected by crankcase oil formulation. In GDI vehicles, deposited engines were found to have increased hydrocarbon and carbon monoxide emissions and poorer fuel economy and acceleration, but lower particulate emissions.

Ethanol-gasoline blends are widely understood to present certain technical challenges to engine operation. Despite widespread use of fuels ranging from E5 (5% ethanol in gasoline) in some European countries to E10 (10% ethanol) in the United States to E100 (100% ethanol; “alcool”) in Brazil, there are certain subjects which have only anecdotally been examined. This paper examines two such issues: the effect of ethanol on intake valve deposits (IVD) and the impact of fuel additive on filter plugging (a measure of solubility). The effect of ethanol on IVD is studied along two lines of investigation: the effect of E10 in a multi-fuel data set carried out in the BMW 318i used for EPA and CARB certification, and the effect of varying ethanol content from 0% to 85% in gasoline carried out in a modern flex-fuel vehicle.

A 100-hour engine dynamometer test for intake valve deposits (IVD) which uses a Ford 2.3L engine was developed by the Coordinating Research Council (CRC). Recently, this test has been approved by the American Society for Testing and Materials (ASTM) as Test Method D 6201-97. Since this test offers improvements in test variability, duration, and cost, it is expected to replace ASTM D 5500-94, a 16,000-km vehicle test run using a BMW 318i, as the key performance test for the Certification of Gasoline Deposit Control Additives by the EPA Final Rule. As a step in the replacement process, a correlation between valve deposit levels for the CRC 2.3L Ford IVD test and ASTM D 5500 BMW IVD test must be determined. This paper provides a statistical review of available data in an attempt to provide such a correlation.

Increasingly stringent vehicle emissions legislation is being introduced throughout the world, regulating the allowed levels of particulate matter emitted from vehicle tailpipes. The regulation may prove challenging for gasoline vehicles equipped with modern gasoline direct injection (GDI) technology, owing to their increased levels of particulate matter production. It is expected that gasoline particulate filters (GPFs) will soon be fitted to most vehicles sold in China and Europe, allowing for carbonaceous particulate matter to be effectively captured. However, GPFs will also capture and accumulate non-combustible inorganic ash within them, mainly derived from engine oil. Studies exist to demonstrate the impact of such ash on GPF and vehicle performance, but these commonly make use of accelerated ash loading methods, which themselves introduce significant variation.

The growing need for improved fuel economy is a global challenge due to continuously tightening environmental regulations targeting lower CO2 emission levels via reduced fuel consumption in vehicles. In order to reach these fuel efficiency targets, it necessitates improvements in vehicle transmission hardware components by applying advanced technologies in design, materials and surface treatments etc., as well as matching lubricant formulations with appropriate additive chemistry. Axle lubricants have a considerable impact on fuel economy. More importantly, they can be tailored to deliver maximum operational efficiency over specific or wide ranges of operating conditions. The proper lubricant technology with well-balanced chemistries can simultaneously realize both fuel economy and hardware protection, which are perceived to have a trade-off relationship.

In the last decade, numerous studies have been conducted to investigate the mechanism of Low Speed Pre-Ignition (LSPI) in Turbocharged Gasoline Direct Injection (TGDi) engines. According to technical reports, engine oil formulations can significantly influence the occurrence of LSPI particularly when higher levels of calcium-based additives are used, increasing the tendency for LSPI events to occur. While most of the studies conducted to date utilized engine tests, this paper evaluates the effect of engine oil formulations on LSPI under real-world driving conditions, so that not only the oil is naturally aged within an oil change interval, but also the vehicle is aged through total test distance of 160,000 km. Three engine oil formulations were prepared, and each tested in three vehicles leading to an identical fleet totaling nine vehicles, all of which were equipped with the same TGDi engine.

1Increasing adoption of downsized, boosted, spark-ignition engines has improved vehicle fuel economy, and continued improvement is desirable to reduce carbon emissions in the near-term. However, this strategy is limited by damaging preignition events which can cause hardware failure. Research to date has shed light on various contributing factors related to fuel and lubricant properties as well as calibration strategies, but the causal factors behind an individual preignition cycle remain elusive. If actionable precursors could be identified, mitigation through active control strategies would be possible. This paper uses artificial neural networks to search for identifiable precursors in the cylinder pressure data from a large real-world data set containing many preignition cycles. It is found that while follow-up preignition cycles in clusters can be readily predicted, the initial preignition cycle is not predictable based on features of the cylinder pressure.

With the increasing use of modern, EGR-equipped, heavy-duty diesel engines and the use of lower sulfur and alternate fuels, such as biodiesel, lubricants are being exposed to a range of different compositions of acids. To complement the traditional detergent bases, todays lubricants have evolved to include a higher proportion of basic materials from amine-derived sources to aid in oxidation and soot control. This paper explores the impact of the different sources of acids, some of the issues they create and how they can be addressed, exemplified in a prototype CJ-4 lubricant formulation.

The popularity of light trucks and sport utility vehicles (SUVs), coupled with growing consumer demand for vehicles with more size, weight and horsepower, has increased the impact of these vehicle classes on the manufacturer's CAFE (Corporate Average Fuel Economy) numbers. Consumers often use light trucks and SUVs in applications such as prolonged towing at highway speeds, resulting in heavy loading and/or high operating temperatures in the axle. These conditions require superior axle lubricant protection, often provided by choosing a higher viscosity fluid (e.g., SAE 75W-140). Traditionally, the choice of these higher viscosity fluids for enhanced durability performance often results in reduced city-highway efficiency. This paper will describe the use of controlled axle dynamometer laboratory testing methods to develop fluids that maximize both fuel efficiency and durability performance across the wide spectrum of the new proposed viscosity classifications.

The popularity of light trucks and sport utility vehicles (SUVs), coupled with growing consumer demand for vehicles with more size, weight and horsepower, has challenged the original equipment manufacturers' (OEM) ability to meet the Corporate Average Fuel Economy (CAFE) specifications due to the increased contribution of these vehicle classes on fleet averages. The need for improved fuel economy is also a global issue due to the relationship of reduced fuel consumption to reduced CO2 emissions. Vehicle manufacturers are challenged to match the proper fluid with the application to provide the required durability protection while maximizing fuel efficiency. Recent new viscosity classifications outlined under SAE J306 aid in more tightly defining options for lubricant choice for a given application. Changes to the SAE J306 viscosity classification define new intermediate viscosity grades, SAE 110 and SAE 190.

Cloud point depressants (CPD) have been successfully used for many years in low-sulfur diesel fuels. For over ten years, custom-designed, specialty polymer chemistry has enabled refiners to meet cloud point (CP) guidelines with substantially less kerosene. This translates into greater refined yields through cut-point adjustment upgrades and the potential for diverting kerosene to more lucrative market opportunities, such as jet fuel. The practice of cut-point downgrades to gas oil can be costly because diesel fuel generally has greater value. Kerosene dilutions have historically been as high as 30%-40% by volume with low-sulfur diesel fuels [1, 2]. While kerosene addition enables fuels to reach CP guidelines, it may negatively impact the fuel's energy content, cetane number, lubricity, flash point and density. Properly designed CP additives are able to substantially reduce or even eliminate the need for kerosene, thus substantially reducing refinery costs.

Many marketers of branded diesel fuels are introducing a “premium” diesel fuel grade. The National Conference on Weights and Measures is recommending that one of the criteria for marketing a fuel as “premium” is that it have a lower cloud point or alternatively a reduced low temperature flow test (LTFT) failure point [1]. However, waxy crudes and process limitations make it difficult for refiners to economically make very low cloud point diesel fuel. Fortunately, cloud point depressants (CPDs) can overcome these limitations. However, refiners are concerned about the effect cloud point additives have on other diesel fuel properties. We found that cloud point depressants allow refiners to meet low temperature specifications while being neutral or beneficial to other diesel fuel properties.

A new gas phase kinetic model using Westbrook's gas phase n-heptane model and Frenklach's soot model was constructed. This model was then used to predict the impact on PAH formation as an indices of soot formation on ethanol/diesel fuel blends. The results were then compared to soot levels measured by various researchers. The ignition delay characteristics of ethanol were validated against experimental results in the literature. In this paper the results of the model and the comparison with experimental results will be discussed along with implications on the method of incorporation of additives and alternative fuels.

A new generation of fluid technology using novel diesel fuel detergent/dispersant chemistry provides a multitude of beneficial effects to the diesel engine, especially the latest model designs. In addition to improved injector, valve and combustion chamber deposit removal, the additive restores power, fuel economy, performance and emission levels1. Positive observations have also been documented along with improved performance concerning crankcase lube viscosity, soot loading and TBN retention. An even greater added benefit is the inherent capability of the fuel additive to deal with several EGR issues now prominent with the introduction of new engines. Recent research, reported herein, has uncovered the extensive efficacy of this chemistry for piston durability and neutralization of ring corrosion phenomena. All of the beneficial additive attributes are further enhanced with increased oxidative and thermal fuel stability and no loss of filterability.

Multifunctional or universal lubricating oils which service both gasoline and diesel engines have gained widespread commercial acceptance. Since 1970, numerous changes and additions have altered the performance tests and specifications which define the quality of these lubricants. New parameters include single cylinder and multicylinder diesel engine testing, valve train wear protection, clutch plate friction retention, extended drain interval and lubricant related fuel economy. In response to these requirements, new additive systems were developed. This paper discusses observed base oil-additive-engine test interactions and compares the performance of one of these additive systems to that of the old.

Motorcycle OEMs faced with stringent global fuel economy and emission regulations are being forced to develop new hardware and emissions control technologies to remain compliant. Motorcycle oils have become an enabling technology for the development of smaller, more efficient engines operating at higher power density. Many OEMs have therefore become reliant on lubricants to not only provide enhanced durability under more extreme operating conditions, but to also provide fuel economy benefits through reduced energy losses. Unlike passenger car oils that only lubricate the engine, motorcycle oils must lubricate both the engine and the drive train. These additional requirements place different performance demands versus a crankcase lubricant. The drive train includes highly loaded gears that are exposed to high pressures, in turn requiring higher levels of oil film strength and antiwear system 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 the durability required for severe service. In light truck/SUV applications, gear oils must provide operating temperature control under extreme conditions such as trailer-towing. Higher operating temperatures for prolonged periods can adversely affect metallurgical properties and reduce fluid film thickness, both of which can lead to premature equipment failures. In our view, operating temperature is an important indicator of durability. Unfortunately, lubricants optimized for temperature control do not always provide the best fuel economy.

The regulatory drive for emission reductions, increased fuel costs, and likely increases in Corporate Average Fuel Economy (CAFE) requirements have made fuel efficiency a key issue for North American vehicle manufacturers and marketers. At the same time the popularity of sport utility vehicles and light trucks has made it more difficult to achieve CAFE objectives. In order to accommodate both public vehicle preference and government mandated CAFE requirements automobile manufacturers are seeking all available means to increase fuel economy through advanced system design, engineered materials, and improved lubricant technology. Axle lubricants can have a significant impact on fuel economy; moreover, axle lubricants can be tailored to deliver maximum operating efficiency over either specific or wide ranges of operating conditions.

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.

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.