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In the next ILSAC passenger car motor oil specification the Sequence IIIG engine test, as well as two versions of the Thermo-Oxidation Engine Oil Simulation Test (TEOST) have been proposed as tests to determine the ability of crankcase oils to control engine deposits. The Sequence IIIG engine test and the TEOST MHT test are designed to assess the ability of lubricants to control piston deposits and the TEOST 33 test is designed to assess the ability of lubricants to control turbocharger deposits. We have previously characterized the chemical composition of Sequence IIIG piston deposits using thermogravimetric, infrared and SEM/EDS analyses. Sequence IIIG piston deposits contain a significant amount of carbonaceous material and the carbonaceous material is more prevalent on sections of the pistons that should encounter higher temperatures. Furthermore, the carbonaceous material appears to be a deposit formed by the Sequence IIIG fuel.

Deposit formation is an issue of great significance in a broad range of applications where lubricants are exposed to high temperatures. Lube varnish causes valve-sticking, bearing failure and filter blockage which can lead to considerable equipment downtime and high maintenance costs. Recently this has become a pressing issue in the stationary power generation industry. In order to investigate the chemistry leading to varnish, three samples of varnish-coated components from the lube/hydraulic systems of gas turbines from the field were obtained, along with information on the commercially available formulated oils which were used. Samples of these three fresh oils were analysed by a variety of chromatographic and spectroscopic techniques, which confirmed chemical identity of aminic and/or phenolic antioxidants, corrosion inhibitors and antiwear components. The varnish-coated turbine components were also investigated by these methods.

This paper provides an overview of driveline fluids, in particular automatic transmission fluids (ATFs), and is intended to be a general reference for those working with such fluids. Included are an introduction to driveline fluids, highlighting what sets them apart from other lubricants, a history of ATF development, a description of key physical ATF properties and a comparison of ATF fluid specifications. Also included are descriptions of the chemical composition of such fluids and the commonly used basestocks. A section is included on how to evaluate used driveline oils, describing common test methods and some comments on interpreting the test results. Finally the future direction of driveline fluid development is discussed. A glossary of terms is included at the end.

Modern light-duty trucks and SUV's are designed to be aerodynamic to increase fuel economy. Such vehicle design significantly reduces the amount of air available to cool the rear axle in rear wheel drive vehicles. Reduced cooling coupled with higher power output and additional load from trailer towing operations results in higher axle operating temperatures, especially during the early operation or “break-in” phase of axle life. Higher axle operating temperatures decrease oil viscosity resulting in reduced oil film formation ability to protect against wear and contact fatigue. High temperature also shortens the useful life of gear oils. To facilitate the development of gear oils capable of reducing axle operation temperature, we have developed a laboratory simulation test method that can closely simulate actual trailer-towing driving on Baker's grade road under maximum GVCWR of close to 6,033 kg (13,300 lbs).

This report describes the results of a fleet test conducted with vehicles certified to Euro IV standards and equipped with high cell density close coupled manifold mounted catalysts. The purpose of the test was to determine the effect of MMT® on vehicle emission system durability under severe in-service operating conditions and to address vehicle manufacturers concerns about the effects of MMT® in advanced technology vehicles. The results clearly show that performance and durability of the vehicles are not affected even under severe operating conditions when MMT® is used in the gasoline. Two pairs each of Volkswagen Passats and Opel Corsas (eight vehicles total) were operated on a base fuel and a base fuel splash blended with MMT® at a concentration of 18 milligrams manganese per liter (“mg Mn/l”). The vehicles accumulated mileage on a driving regime representative of severe service.

Since the mid-1990's, original equipment manufacturers (OEMs) of automobiles have been implementing torque converter clutches in automatic transmissions with a continuous, controlled slip mode, in order to improve the fuel economy of their vehicles. These Continuously Slipping Torque Converter Clutches (CSTCCs) are prone to an undesirable phenomenon commonly called shudder. This phenomenon has been attributed to specific shapes or slopes in the friction coefficient versus sliding speed curve of the fluid/clutch interface. Here, a method is explained that was developed to be able to screen fluids for shudder tendency, both in fresh and used states. Also included is a description of the reason for implementing CSTCCs, some background on shudder, and supporting data showing how the test method can distinguish between fluids that have different shudder tendencies.