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Interactions between a Zinc dialkyldithiophosphate (ZDP) and three different commercially available succinimide dispersants were observed through changes in solutions behavior, as determined by viscometry and Fourier Transform Infrared spectroscopy (FTIR), and four-ball tests. The viscometric response observed for two component blends of ZDP and succinimide dispersant in white oil changed as a function of the molar Zn to N ratio, indicative of specific interactions. The break in the viscometric response curve occurred at Zn:N=0.13 for all three succinimide dispersants. FTIR spectra of the same ZDP-dispersant blends were examined and similar Zn:N dependencies were observed. Four-ball tests measuring wear scar diameter, seizure load and weld load showed a dependence on the Zn to N ratio similar to that observed by viscometry. At very low Zn to N ratios wear and seizure load were decreased, while at higher ratios the seizure and weld loads were increased over that for ZDP alone.

Despite the many years of widespread use of the BMW Intake Valve Deposit (IVD) vehicle test, relatively little has been published quantifying the variation in the test procedure. This paper presents an analysis of the variability in the BMW test. Though results from 8045 km (8K; 5,000 mile) tests rather than 16090 km (16K; 10,000 mile) are highlighted due to the size of the available database and relative sensitivity of the data, analysis suggests that variation at 8K is representative of 16K variation. A square root transformation of average deposit weight at 8K, though more cumbersome than the more common log transformation, is found to be the most appropriate way to eliminate the dependence of variation on the absolute level of deposits. Within-car variation is found to account for over half of the test-to-test variation, contradicting the notion that car-to-car differences are the dominant source of variability.

Our basic understanding of the chemical and physical nature of soot, its interaction with lubricant components and its role in promoting wear and oil thickening in heavy duty diesel engines continues to grow. Our current study in the GM 6.5L engine focuses on examining the effects of variations in base stock type (Group I vs. Group II), viscosity index improver or viscosity modifier (VM) chemistry (OCP vs. dispersant OCP), zinc dithiophosphate (ZDP) type and dispersant type (low MW vs. high MW) on roller follower wear, viscosity growth and other measured responses. In this study, more robust fluids were tested producing very low wear results and minimal viscosity increase of the lubricant. Fluids containing dispersant OCP (DOCP) and high MW dispersant produced a lower degree of wear, whereas varying the ZDP type (1° vs. 2°) showed no effect on wear. The use of Group II base stocks was associated with significantly lower viscosity increases.

Extended drain of axle and transmission lubricants has gained wide acceptance in both passenger car and commercial vehicle applications. Understanding how the lubricant changes during extended drain operations is crucial in determining appropriate lubricants and drain intervals for these applications. A suitable aging screen test with an established relationship to field performance is essential. Over the years numerous methods have been studied (DKA, GFC, ISOT, ASTM L-60) with varying degrees of success1,2,3. Current methods tend to be overly severe in comparison to field experience, hence the need for further work in this area. As a result of recent work, a lubricant aging test method has been developed which shows good correlation with field experience, giving us an effective tool in the development of long drain oils.

In API engine oil licensing, candidate oils must meet the performance requirements of category defined engine tests. While API category engine tests are developed to target a theoretical performance standard, it is rare that the cost to test and approve oils is understood. Given that engine tests are an integral part of oil evaluation, understanding of engine test value is necessary. Therefore, measurements of value are presented as Unbiased Engine Test Evaluation (UETE). UETE evaluates an engine test's draw on time and money resources by estimating the average number of tests required before a candidate oil will pass the category defined engine tests. A pilot study using the API CH-4 Category is presented.

With the 8HP transmission generation, ZF established a model range on the market offering considerable progress in terms of fuel savings, power-to-weight ratio, and functionality. A front-transverse transmission derived from the 8HP transmission generation gear set concept leads to higher design costs and to an unfavorable design, contradicting the very restricted installation spaces for front-transverse transmissions. With the transmission concept of the 9HP48 transmission, the advantages of the 8HP transmission generation were successfully transferred to a front-transverse transmission design and, at the same time, all restrictions regarding the installation space were solved. Thanks to its number of gears the high efficiency and the reduced drag torque, the 9HP48 transmission delivers fuel savings of up to 16 percent compared with today's standard 6-speed automatic transmissions with front-transverse installation.

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). The durability of this fuel economy improvement is becoming increasingly important and will be address in the successor to the Sequence VIA, the Sequence VIB, which is currently under development for ILSAC GF-3. Previous investigations have indicated that the choice of detergent system and friction modifier has a large impact on the fuel economy of a lubricant. As a result of a study undertaken to further investigate these effects in a 1994 Ford Crown Victoria running the EPA Federal Test Procedure, a significant impact on tailpipe emissions was discovered. Detergent system affected both regulated emissions (hydrocarbon (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) emissions), and non-regulated emissions (carbon dioxide emissions).

Shim bond coverage analysis is a common practice in brake and pad manufacturing during brake pad development. This analysis is used to assess the quality of a shim bond and quantify it in case of any quality or de-bond issues during production and warranty returns. Currently, the analysis is carried out manually in the industry using a 1:1 template printed on tracing paper, which is placed on the deboned shim to identify bad bonded regions. The bond coverage is then calculated manually based on the data obtained from the template, which is a time-consuming process taking around 15 minutes per pad/shim analysis. To minimize manual work and increase accuracy, artificial intelligence is being used to estimate the shim bonding quality and coverage. The idea is to feed the deboned shim and pad picture to the model and predict the following: Whether the bond coverage is good or bad. Identify the good/bad and unnecessary regions on the shim/pad for bond coverage analysis.

Intentionally adding water to oil, in the laboratory, provides an indication of the oil's ability to tolerate the presence of water. Various characteristics, such as emulsion, haze or separation, may be observed. Some blends of oil and water have been shown to form structures when left undisturbed. A visual, qualitative, storage test is capable of detecting this phenomenon as the presence or absence of structure. However, the time frame of formation can be on the order of days or weeks and is sensitive to handling and temperature effects. Quantitative methods are required for any evaluation of chemistry, temperature and handling effects on the rate and strength of structure formation. This paper describes rheological and electrical methods which directly and indirectly measure the tendency to form a structure at the molecular level, yielding rate of formation and strength information.

In recent years, fuzz testing has established itself as a reliable and indispensable testing method for finding previously unknown and product specific vulnerabilities within the code base of automotive systems. As such, we see increased requirements for automotive products that call for fuzz testing per default. Based on the semidecidable characteristic for finding fuzz testing results, i.e., virtually an infinite test space, it is a non-trivial task to generate plausible evidence that sufficient fuzz testing has been applied to the target system. In this paper, starting from fuzz test result generation, we specify the individual steps necessary for preparing a sound evidence report. We describe how evidence is created in this context and which information is relevant. The traceability of fuzz testing product requirements is a driving factor thereby.

The legislative and market pressure for CO2 reduction and fuel efficient powertrains lead to a variety of automatic transmission concepts in recent years. The CVT technology, the dual clutch technology (DCT) and optimized architectures of torque converter / planetary gear based automatic transmissions (AT), such as 6, 7, and 8 speed ATs entered the market in the last decade. Also different hybrid technologies have entered the market offering further improvement for fuel consumption especially in city driving. Helpful for OEMs and suppliers to flexibly meet market demands proofed the use of modular hybrid solutions. Clear demand to meet were packages of existing vehicles and powertrains with AT and hybrid transmission (HT), e.g. the modular transmission kit based on the ZF 8 speed AT. Hybrid technology is offering fuel efficiency benefits, but there are also reasons for a slow market penetration.

The relationship between 76 Racing and NASCAR allowed 76 Lubricants Company to work closely with Richard Childress Racing (RCR) and The Lubrizol Corporation in the development of oil screening and analytical test procedures which permit rapid evaluation of potential top-tier NASCAR race oils. The oils were designed to meet the challenge of increasingly severe engine operating parameters. This paper will discuss dynamometer testing and how properties of the oil such as viscosity grade, base fluid, and additives affect engine durability in the dynamometer test program and performance at the track in NASCAR Winston Cup Racing. Areas of growing concern include the cam/lifter contact, ring/liner contact, wrist pin/pin bore and wrist pin bushing contacts. Racing lubricants must withstand these harsh conditions for periods of 3-4 hours of continuous running.

Friction material manufacturing is a complex process where numerous raw materials are mixed, pressed, and cured to make brake pads. It is important to have a consistent manufacturing process that can produce a brake pad that satisfies the vehicle braking requirements. A basic and critical requirement for any brake pad is structural integrity with no internal cracks. In this work a series of processing changes were made to intentionally produce internal cracks in the friction material. Various pad crack detection methods were studied, and their advantages and disadvantages are discussed in detail. One of the crack detection methods used an ultrasonic measuring instrument which gives objective data in the form of calculated modulus of elasticity and signal loss. The details of the machine and how the measurements are obtained are discussed. The modulus calculation is also described.

Hydrodynamic launch elements, from the Foettinger principle of the torque converter to the first series production HCC wet clutch, are becoming more relied on in the transmission world for their high power density, launch comfort, and vibrational isolation capability. In order to attain the ambitious fuel economy objectives of the future, engine vibrations have to be successfully isolated from the driveline at low engine speed ranges without the use of the hydrodynamic circuit. This is now all the more challenging as new combustion engines are producing higher torsional vibrations as a result of fewer cylinders, higher combustion pressures, cylinder deactivation, and lower critical speeds. This paper will describe the next generation of powertrain vibrational isolation, dampening via powersplit. Additionally, a next generation wet launch element, the Hydrodynamically Cooled Clutch will be discussed.

Information relative to oil thickening has been developed in road tests. Typical operating temperatures, as well as the length of time required to thicken oils in these tests, are described. A laboratory test procedure has been developed that shows a good degree of correlation with this field service. The effect of test conditions such as jacket temperature and piston ring design on oil thickening in the laboratory are described.

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.

The lubricant is a key component in the successful operation of a manual transmission, but it is important that the interactive effects with the friction material are understood. This paper examines the effect of several key additive components on the friction and wear performance of a single sinter composition in a carefully controlled laboratory test. In addition, the test method allows one to develop information about the shift behavior of the fluid-synchronizer material combination which provides useful information about shift quality. From the original experimental design program a predictive model was developed and an optimized formulation was tested as a validation of the results.

Inconsistent fuel filter life is a problem that continues to plague most heavy-duty diesel fleets. It has been proven that fuel filter life can be strongly influenced by the thermal and oxidative stability of diesel fuel that is being filtered. Filters consistently exposed to diesel fuels that produce a tar-like substance in abundance upon heating (sometimes termed “asphaltenes”) will plug far more rapidly than filters exposed to diesel fuel that does not easily form these tar-like substances. Fuel additives have long been used to maintain fuel system cleanliness and to improve diesel fuel stability. It follows logically that such additives could have a positive impact on fuel filter life by maintaining the cleanliness of the fuel filtration media. This paper reviews the laboratory evaluations and field tests that were run to compare fuel filter life in both the presence and absence of diesel fuel additives.

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.

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.