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Limited technical studies to speciate particulate matter (PM) emissions from gasoline fueled vehicles have indicated that the lubricating oil may play an important role. It is unclear, however, how this contribution changes with the condition of the lubricant over time. In this study, we hypothesize that the mileage accumulated on the lubricant will affect PM emissions, with a goal of identifying the point of lubricant mileage at which PM emissions are minimized or at least stabilized relative to fresh lubricant. This program tested two low-mileage Tier 2 gasoline vehicles at multiple lubricant mileage intervals ranging from zero to 5000 miles. The LA92 cycle was used for emissions testing. Non-oxygenated certification fuel and splash blended 10% and 20% ethanol blends were used as test fuels.

Considerable development effort has shown that conventional diesel engine lubricating oil specifications do not define the needs for acceptable injector life in methanol-fueled, two-stroke cycle diesel engines. A cooperative program was undertaken to formulate an engine oil-fuel additive system which was aimed at improving performance with methanol fueling. The performance feature of greatest concern was injector tip plugging. A Taguchi matrix using a 100 hour engine test was designed around an engine oil formulation which had performed well in a 500 hour engine test using a simulated urban bus cycle. Parameters investigated included: detergent level and type, dispersant choice, and zinc dithiophosphate level. In addition, the influence of a supplemental fuel additive was assessed. Analysis of the Taguchi Matrix data shows the fuel additive to have the most dramatic beneficial influence on maintaining injector performance.

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.

The introduction of fatty acid methyl ester (FAME) into the diesel pool has led to an increase in the incidence of diesel fuel filter blocking. In contrast to conventional diesel, filter blocking events can occur above a fuel's Cloud Point (CP). It has been shown that this phenomenon is due to trace levels of impurities carried over from the original oil source into the final fuel. The two species identified as being the main cause of the filtration problems are saturated monoglycerides (sMG) and sterol glucosides (SG). Reported in this paper is an extensive study completed to understand the impact that these impurities have on the filterability of FAME and FAME containing fuels. This has been investigated using laboratory based filterability tests that incorporate a specific cold soak and the critical contaminant levels causing failure have been determined.

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.

Phosphorus is known to reduce effectiveness of the three-way catalysts (TWC) commonly used by automotive OEMs. This phenomenon is referred to as catalyst deactivation. The process occurs as zinc dialkyldithiophosphate (ZDDP) decomposes in an engine creating many phosphorus species, which eventually interact with the active sites of exhaust catalysts. This phosphorous comes from both oil consumption and volatilization. Novel low-volatility ZDDP is designed in such a way that the amounts of volatile phosphorus species are significantly reduced while their antiwear and antioxidant performances are maintained. A recent field trial conducted in New York City taxi cabs provided two sets of “aged” catalysts that had been exposed to GF-4-type formulations. The trial compared fluids formulated with conventional and low-volatility ZDDPs. Results of field test examination were reported in an earlier paper (1).

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.

A variety of additives are used in automotive diesel fuel to meet specification limits and to enhance quality. For example, lubricity additives and cold flow improvers are used to meet specifications whilst diesel detergents further enhance the quality of the fuel. Recently, several premium fuels that use high levels of diesel detergents and, in some cases, cetane improver have been introduced in the market place. The purpose of the work carried out was to assess the potential impact of these additives on vehicle performance. In order to do this, a fuel free of any additive was treated with very high levels of all the diesel fuel additives currently used to meet specification limits and to enhance diesel fuel performance. A common rail vehicle using an advanced common rail system was then driven in a controlled manner for 50.000 km. Emissions and driveability tests took place at 0km to provide baseline data.

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.

One of the key functions of lubricating oil additives in diesel engines is to control oil thickening caused by soot accumulation. Over the last several years, it has become apparent that the composition of the base oil used within the lubricant plays an extremely important role in the oil thickening phenomenon. In particular, oil thickening observed in the Mack T-8 test is significantly affected by the aromatic content of the base oil. We have found that the Mack T-8 thickening phenomenon is associated with high electrical activity, i.e., engine drain oils which exhibit high levels of viscosity increase show significantly higher conductivities. These findings suggest that electrical interactions are involved in soot-induced oil thickening.

Life Cycle Assessment (LCA) is a methodology used to determine quantitatively the environmental impacts of a range of options. The environmental community has used LCA to study all of the impacts of a product over its life cycle. This analysis can help to prevent instances where a greater degree of environmental harm results when changes are made to products based on consideration of impacts in only part of the life cycle. This study applies the methodology to engine lubricants, and in particular chlorine limits in engine lubricant specifications. Concern that chlorine in lubricants might contribute to emissions from vehicle exhausts of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), collectively called PCDD/F, led to the introduction of chlorine limits in lubricant specifications. No direct evidence was available linking chlorine in lubricants to PCDD/F formation, but precautionary principles were used to set lubricant chlorine limits.

Wet clutch friction devices are the primary means by which torque is transmitted through many of today's modern vehicle drivelines. These devices are used in automatic transmissions, torque vectoring devices, active on-demand vehicle stability systems and torque biasing differentials. As discussed in a previous SAE paper ( 2006-01-3271 - Next Generation Torque Control Fluid Technology, Part II: Split-Mu Screen Test Development) a testing tool was developed to correlate to full-vehicle split-mu testing for limited slip differential applications using a low speed SAE #2 friction test rig. The SAE #2 Split-Mu Simulation is a full clutch pack component level friction test. The purpose of this test is to allow optimization of the friction material-lubricant hardware system in order to deliver consistent friction performance over the life of the vehicle.

Wet clutch friction devices are the primary means by which torque is transmitted in many of today's modern vehicle drivelines. These devices are used in automatic transmissions, torque vectoring devices, active on-demand vehicle stability systems, and torque biasing differentials. As discussed in a previous SAE paper ( 2006-01-3270 - Next Generation Torque Control Fluid Technology, Part I: Break-Away Friction Slip Screen Test Development), a testing tool was developed to simulate a limited slip differential break-away event using a Full Scale-Low Velocity Friction Apparatus (FS-LVFA). The purpose of this test was to investigate the fundamental interactions between lubricants and friction materials. The original break-away friction screen test, which used actual vehicle clutch plates and a single friction surface, proved a useful tool in screening new friction modifier technology.

Characteristics of E diesel, a fuel blend of diesel fuel and ethanol, are considered in a matrix of tests. One characteristic of particular concern and a subject of this investigation is that of stability. Methods to evaluate stability are looked at and compared in light of the potential for distillate and ethanol to separate under certain conditions. The quality of the fuel blend is enhanced by the use of enabling additives to ensure stability which necessitates development of a standard for assessment of the quality of stability. The properties of various base diesel fuels and their influence on stability are also studied. Other key characteristics are evaluated including viscosity, pour point, and oxidative stability.

Recently, research and testing of oxygenated diesel fuels has increased, particularly in the area of exhaust emissions. Included among the oxygenated diesel fuels are blends of diesel fuel with ethanol, or E diesel fuels. Exhaust emissions testing of E diesel fuel has been conducted by a variety of test laboratories under various conditions of engine type and operating conditions. This work reviews the existing public data from previous exhaust emissions testing on E diesel fuel and includes new testing performed in engines of varied design. Emissions data compares E diesel fuel with normal diesel fuel under conditions of different engine speeds, different engine loads and different engine designs. Variations in performance under these various conditions are observed and discussed with some potential explanations suggested.

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.

Diesel fuel is a blend of various middle distillate components separated at the refinery. The composition and characteristics of the diesel fuel blend changes daily if not hourly because of normal process variation, changing refinery processing conditions, changing crude oil diet or changing diesel fuel and kerosene market conditions. Regardless of the situation going on at the refinery or the market, the resultant diesel fuel must consistently meet established cloud point specifications. To consistently meet the cloud point specifications, refiners are forced to blend their diesel fuels in such a way that the resultant blend is always on the low side of the cloud point specification even when the refining process adversely changes the fuel characteristics. This practice has the effect of producing several degrees of cloud point “giveaway” when the refinery is not experiencing adverse swings in product quality.

The Co-ordinating European Council (CEC) for the development of performance tests for transportation fuels, lubricants and other fluids has set up a working group to develop a laboratory pump rig test able to discriminate between diesel fuels of different lubricity performance. This test was expected to correlate with the performance of fuels and Fuel Injection Equipment (FIE) in the field, therefore providing a way to avoid costly field trials. This test could also enhance the understanding of the results from the High Frequency Reciprocating Rig (HFRR) method. The CEC working group was supported by representatives of Oil Companies, Test Houses, Additive Companies and all the European FIE Manufacturers. After a thorough investigative phase, the group focused on a Bosch VE 4 distributor-type pump run according to the Bosch WP2 test cycle. This choice was also widely accepted throughout the industry.

This paper describes the development of an extended vane pump test procedure utilizing the Eaton® 35VQ-25 vane pump. Evaluation of two commercial Zinc Dithiophosphate containing and two commercial non Zinc (ashless) hydraulic fluids are also described. Results show that extending the test time allows differentiation among fluids which give comparable performance in the standard 50 hour test. System cleanliness, as well as pump weight loss, must be used in the performance assessment.

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.