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Four 1998 Mitsubishi Carismas, two equipped with direct injection (GDI) and two with port fuel injection engines (PFI) were tested in a designed experiment to determine the effect of mileage accumulation cycle, engine type, fuel and lubricant type on engine wear and engine oil performance parameters. Fuel types were represented by an unadditised base fuel meeting EEC year 2000 specifications and the same base fuel plus synthetic deposit control additive packages. Crankcase oils were represented by two types (1) a 5W-30 API SJ/ILSAC GF-2 type engine oil and (2) a 10W-40 API SH/CF ACEA A3/ B3-96 engine oil. The program showed that specific selection of oil additive chemistry may reduce formation of intake valve deposits in GDI cars.. In general, G-DI engines produced more soot and more pentane insolubles and were found to be more prone to what appears to be soot induced wear than PFI engines.

The Cooperative Lubrication Research (CLR) Oil Test Engine, usually called the L-38, has been used for nearly 25 years to evaluate copper-lead journal bearing protection of gasoline rnotoroils under high-temperature, heavy-duty conditions. The test is sensitive to aggressive surface active additives that may encourage bearing corrosion. The L-38 also provides an estimate of oil durability, assessing the resistance of an oil to the accumulation of acidic by-products of combustion that could attack copper-lead bearings. However, the L-38 engine dynamometer test uses a heavily leaded gasoline that is no longer representative of the commercial fuels available in North America, Europe, or Japan. Rather than discard the L-38, this paper describes work to modify the L-38 procedure to run with unleaded gasoline.

The constant velocity joint (CVJ) has seen increased usage driven by the growth of front wheel drive vehicles over the last 30 years. The CVJ provides a smooth, dynamic connection between the output of the axle or gearbox and the driving wheels of the vehicle. The seemingly simple device, however, requires specially designed greases to maximize protection of the internal components from distress and provide optimum performance and service life. One measure of potential distress in the CVJ can be related to temperature rise which is a reflection of the friction and wear properties of the grease employed. A test rig was designed and a method created to evaluate the temperature response of different greases used in a CVJ. The test rig was designed to allow a wide range of speeds, torques and shaft angles to be used. The rig uses a unique temperature pickup system to allow for dynamic measurement of the grease temperature in the boot.

Increased awareness of preserving the environment has motivated the development of a wide variety of environmentally compatible products. Such products include environmentally compatible lubricants. Sale and use of these types of lubricants illustrates diligence by the lubricant manufacturer, original equipment manufacturer (OEM), and the consumer in contributing to a cleaner environment. The use of this type of lubricant could enhance the image of the lubricant manufacturer and vendor as well as the equipment manufacturer who employs such a fluid. To base such a lubricant on a vegetable oil creates a product environmentally friendly by its farming origin and its ability to readily biodegrade if released. No machinery is so uniquely suited to using vegetable oil based lubricants as agricultural equipment. Since this equipment is particularly close to the environment, the lubricant can easily come in contact with the soil, ground water, and crops.

Nylon is used as a material in the design of various components of automatic transmissions. Pump rotor guides and thrust washers are among components designed from nylon. Nylon must be compatible with automatic transmission fluid (ATF). An immersion test using nylon strips in various test fluids was developed. The nylon color change was independent of the physical properties (as measured by change of tensile force) of the material. Testing indicated that nylon color change is catalyzed by oxidation effects, and the change in tensile strength is related to thermal degradation. An automatic transmission fluid (ATF) containing calcium sulfonate detergent showed better oxidation resistance and caused less loss of tensile strength in nylon 6 (PA6).

It has long been understood that the piston assembly of the internal combustion engine accounts for a significant proportion of total engine friction. Modern engines are required to have better fuel economy without sacrificing durability. The pursuit of better fuel economy drives trends like downsizing, turbocharging and direct injection fuelling systems that increase cylinder pressures and create a more arduous operating environment for the piston ring / cylinder bore tribocouple. The power-cylinder lubricant is therefore put under increased stress as modern engine technology continues to evolve. The conventional approach to investigating fundamental power-cylinder tribology employs bench-tests founded on assumptions which allow for simplification of experimental conditions.

The ASTM D6121 (L-37) is a key hypoid gear lubricant durability test for ASTM D7450-08 (API Category GL-5) and the higher performance level SAE J2360. It is defined as the ‘Standard Test Method for Evaluation of Load-Carrying Capacity of Lubricants Under Conditions of Low Speed and High Torque Used for Final Hypoid Drive Axles’. Pass/fail is determined upon completion of the test by rating the pinion and ring gears for several types of surface distress, including wear, rippling, ridging, pitting, spalling and scoring. Passing the L-37 in addition to the other tests required for API Category GL-5 credentials, as well as the more strenuous SAE J2360 certification, requires in-depth formulating knowledge to appropriately balance the additive chemistry. This paper describes the results of ASTM D6121 experiments run for the purposes of better understanding gear oil durability.

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 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.

The next generation of engine oil under development has been formulated to maintain beneficial oil lubrication properties at increased engine operating temperatures, increased drain-oil intervals, and with the recirculation of exhaust gas back through the engine (EGR). These conditions result in the formation of degradation products from decomposed fuel, additives, and base oil. Decomposition products containing reactive sulfur can result in the corrosion of copper alloys. Sulfur-containing compounds currently used in these formulations can include zinc dithiophosphates (ZDP), molydithiophosphates, molydithiocarbamates, and molybdic acid/amine complexes, along with sulfur containing detergents and antioxidants. Interactions among these components and others in the formulation often determine the propensity of these formulations for corrosion. This paper will discuss the results of corrosion bench tests used to screen oil formulations for copper corrosion.

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.

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.

The Coordinating European Council, CEC, develops performance tests for the motor, oil, petroleum, additive and allied industries. In recent years, CEC has moved away from using round robin programmes (RRP's) for monitoring the precision and severity of test methods in favour of regular referencing within a test monitoring system (TMS). In a TMS, a reference sample of known performance, determined by cross-laboratory testing, is tested at regular intervals at each laboratory. The results are plotted on control charts and determine whether the installation is and continues to be fit to evaluate products. Results from all laboratories are collated and combined to monitor the general health of the test. The TMS approach offers considerable benefits in terms of detecting test problems and improving test quality. However, the effort required in collating data for statistical analysis is much greater, and there are technical difficulties in determining precision from TMS data.

The laboratory tests used to define API GL5 have been the cornerstone of gear oil development for well over thirty years. In that time they have served the market very well. Lubricants developed with these test methods have provided adequate protection of axle components from severe wear, scuffing, corrosion, and oxidation. Recently, however, there has been an increasing trend toward extended drain intervals which changes the picture. Coupled with longer oil drain intervals there is a continuing increase of power throughput in the equipment. The combination of increased power and extended service life places significant stress on the oil such that the load carrying ability and thermal and oxidative stability could be greatly diminished under these conditions. During the past ten years the industry has been actively working toward a new gear oil specification that will address the performance needs of today's vehicles.

The specific goal of this project was to determine if there is a difference in the lube oil degradation rates in a heavy-duty diesel engine equipped with an EGR system, as compared to the same configuration of the engine, but minus the EGR system. A secondary goal was to develop FTIR analysis of used lube oil as a sensitive technique for rapid evaluation of the degradation properties of lubricants. The test engine selected for this work was a Caterpillar 3176 engine. Two engine configurations were used, a standard 1994 design and a 1994 configuration with EGR designed to meet the 2004 emissions standards. The most significant changes in the lubricant occurred during the first 50-100 hours of operation. The results clearly demonstrated that the use of EGR has a significant impact on the degradation of the engine lubricant.

Studies of selected automotive gear lubricants in heavy truck tandem axles and transmissions have revealed improvements in fuel economy associated with the viscosity of lubricants tested (grades 75W, 75W-90, and 80W-140). The testing included a heavy truck on-highway fleet test and test track operation. Standard laboratory gear tests on light viscosity monograde (SAE 75W) oils indicate that oils of this type may be deficient in EP protection. Combined observations show that there may be a critical balance between axle lubricant fuel economy benefits and axle durability in field service.

The effects of lubricating oil on friction and wear were investigated using light-duty 2.2L compression ignition direct injection (CIDI) engine components for bench testing. A matrix of test oils varying in viscosity, friction modifier level and chemistry, and base stock chemistry (mineral and synthetic) was investigated. Among all engine oils used for bench tests, the engine oil containing MoDTC friction modifier showed the lowest friction compared with the engine oils with organic friction modifier or the other engine oils without any friction modifier. Mineral-based engine oils of the same viscosity grade and oil formulation had slightly lower friction than synthetic-based engine oils.