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A 100,000-mile fleet test was carried out on nine 1991 gasoline-powered passenger cars employing an API SH/CD motor oil and two reduced phosphorus analogues. The lower-phosphorus oils have zinc dialkyldithiophosphate (ZDDP) treat rates that fall below the proposed ILSAC GF-2 maximum phosphorus limit (0.11%). Gaseous tail pipe emissions were measured at various intervals according to the EPA FTP City Emissions Test 75 driving cycle. A good correlation between phosphorus level and emissions degradation was obtained when starting emissions levels and oil consumption was accounted for in the analysis. Few differences were observed between the highest-phosphorus oil (0.11%) and the lower-phosphorus (0.08% and 0.06%) oils in the typical end of test engine cleanliness parameters. There were no significant differences in either valve train or cylinder wear between the oils. The used oils had similar analytical inspections.

A 100,000-mile fleet test in nine gasoline-powered passenger cars was carried out. The impact of motor oil phosphorus levels on engine durability, oil degradation, and exhaust emissions has been previously described. The results of additional emissions control systems studies, and measurements of the engine oil additive elements which are present on the catalysts, are now presented. These studies include conversion efficiencies for the aged catalyst at the end of the test by a combination of light-off experiments, air/fuel sweep tests, and an auto-driver FTP. The performance of the lambda sensors is also presented. The relationships between engine oil additive levels and composition and emissions systems durability is presented.

The oxidation of surrogate diesel fuels composed of mixtures of three pure hydrocarbons with and without their cetane numbers chemically enhanced using 2-ethylhexyl nitrate (2-EHN) is studied in a variable pressure flow reactor over a temperature range 500 - 900 K, at 12.5 atmospheres and a fixed reaction time of 1.8 sec. Changes in both low temperature, intermediate temperature, and hot ignition chemical kinetic behavior are noted with changes in the fuel cetane number. Differences appear in the product distribution and in heat release generated in the low and intermediate temperature regimes as cetane number is increased. A chemically enhanced cetane fuel shows nearly identical oxidation characteristics to those obtained using pure fuel blends to produce the enhanced cetane value. The decomposition chemistry of 2-EHN was also studied. Pyrolysis data of 10% 2-EHN in n-heptane and toluene are reported.

This paper traces the evolution of the ASTM Test Monitoring Center (TMC) from its modest beginnings in 1976 to the present. Formed as an unbiased and non-aligned group within ASTM Subcommittee D02.B, the TMC operates a reference oil based calibration system that serves both the producers and users of automotive lubricants. Governed by the ASTM Test Monitoring Board, the center's primary mission is to calibrate engine dynamometer test stands used to conduct various ASTM test methods for evaluating lubricant performance. The core services of the TMC have remained the same over its nearly 25 year history. The center stores and distributes ASTM reference oils and is responsible for assuring, through the use of analytical testing, the quality and consistency of the oils. The number of reference oils handled by the TMC has steadily increased over time such that today the center inventories some 100 different formulations having a total volume of 65,000 gallons.

Major engine-design features of the 17.6 cu in. engine are described and engine development is traced by photographs and sectional drawings. Fuel testing with the 17.6 engine produced these results: ratings were obtained of many API-NACA pure hydrocarbons, which permitted relating variable compression-ratio results with supercharged results; Army-Navy performance numbers above 100 were established; the most sensitive fuels were indicated to be most prone to failure by preignition. The engine also contributed greatly to the development of spark plugs. The catalytic effects of spark plug electrode materials on the ignition of methyl alcohol and unleaded benzene are discussed.

USEFUL test procedures and instrumentation for evaluating the effects of combustion chamber deposits are described here. A multi-cylinder deposit-ignition counter has been developed which detects and records the deposit ignition occurring in the individual cylinders of a multicylinder engine. This new instrument measures basic deposit effects over a wide range of engine operating conditions and can be used either in the laboratory or on the road. The instrument is useful for studying the effects of fuels, lubricants, and additives in multi-cylinder engines. Since variation among individual cylinders can be detected, the instrument is also useful for studying engine design changes as well as operating conditions. Road and dynamometer test procedures for evaluating deposit-induced autoignition by the conventional audible method of detection are described along with the effects of several fuel-lubricant-additive combinations.

THIS paper represents a method by which the knocking characteristics of automotive engines may be compared in relation to the Research Method and Motor Method engines. The effects of many engine variables on the ratings of sensitive fuels in passenger-car engines are illustrated. These variables include compression ratio, engine speed, air density, distributor tolerances, and temperature. Direct comparisons are made of the manner in which 1955 passenger cars utilize fuel antiknock quality. It is indicated that two knock test methods must be used to achieve fuel quality control as fuel quality is recognized by engines operated in passenger cars.

The use of lead-free gasoline in conventional passenger car engines poses some problems that are discussed in this paper. Under heavy-duty operation, severe exhaust valve seat wear may occur. This will eventually result in one or more valves remaining open with extremely high exhaust emissions. The combustion chamber deposits formed in the absence of lead are typically more carbonaceous. These deposits have a higher heat capacity than lead deposits and the result, after extended mileage, is higher octane number requirements for the engines operated on nonleaded gasoline. The use of aromatic blending stocks to increase the octane number of nonleaded fuels to approach the octane quality of today's leaded gasolines increases undesirable exhaust emissions. The amounts of phenol, benzaldehyde, and total aromatic aldehydes in the exhaust gas are directly proportional to the aromaticity of the fuel.

ALTHOUGH there is no substitute for practical experience, this paper will provide useful guidance for those who are contemplating engine cylinder pressure measurements for the first time. A frank discussion of the dangers inherent in some common assumptions and short cuts illustrates the need for continuous appraisal of test methods even by veteran users of engine indicator equipment. The new techniques and new transducers described may stimulate rapid advances in the art.

A laboratory Ball Rust Test (BRT) has been jointly developed by General Motors and Ethyl Corporation to replace the current Sequence IID engine test, and standard test procedures have been established to assess the rust/corrosion protection ability of experimental and commercial oils. Under the optimum test conditions developed, BRT data on eight industry reference and eighteen industry supplied oils showed a reasonable correlation with Sequence IID average rust test results. The capability of the BRT for differentiating oil quality was further demonstrated by evaluating 132 commercial oils obtained from around the world: oils with insufficient protection, such as those with API performance ratings of SA to SE, performed poorly in the BRT; oils with API ratings of SF, SG, and SH performed well in the test. The BRT will be made available to ASTM for development of a precision statement and for inclusion in future engine oil performance specifications.

DEPOSIT-induced ignition (the erratic ignition of the fuel-air mixture by combustion chamber deposits) is one of the problems hindering the development of higher compression, more efficient engines. Deposit-induced ignition results in uncontrolled combustion, which often is followed by knock. In some modern engines, the suppression of knock originating through this mechanism may require higher fuel antiknock quality than that required to suppress ordinary knock. Fuel composition and volatility have been found to affect the amount of deposit ignition. Reduction in fuel end point reduces deposit ignition. Among individual leaded hydrocarbons, aromatics produce by far the most deposit ignition, but the differences among full-boiling gasoline stocks of similar volatility do not appear to be related to their hydrocarbon-type proportions. Engine operating conditions favorable to carbon formation tend to increase deposit ignition and magnify differences among fuels.

THIS paper discusses a number of factors involved in the problem of octane-number requirement increase due to combustion-chamber deposits. A laboratory single-cylinder engine test procedure, which evaluates the effects of various fuel and oil factors, is presented with data showing its correlation with passenger-car operation under light-duty, city-driving conditions. The influence of engine operating conditions during accumulation of deposits and the importance of engine conditions selected to evaluate the magnitude of the requirement increase are illustrated. It is indicated that organic materials formed from both fuel and oil are of major importance in deposit formation. Data are presented which show that tel added to pure hydrocarbons of different chemical types may have different effects. It is shown that the carbon/hydrogen ratio of leaded pure hydrocarbons influences the amount and composition of the deposit formed.

Greenhouse gas emissions (GHG) from light-duty vehicles have received attention recently because of increased focus on global warming and climate change. Relative to emissions of regulated pollutants like hydrocarbons and nitrogen oxides, nitrous oxide (N2O) emissions from all vehicles are generally very low. However, N2O is a powerful greenhouse gas, and small emissions of N2O can contribute substantially to total GHG inventories. Two fleets of different vehicle models, both meeting the current US Tier 1 emission standard, were evaluated in an effort to develop a better understanding of N2O emissions from modern three-way catalyst-equipped vehicles. Nine 1997 Ford Crown Victoria vehicles operating on clean-burning US Federal Phase 2 Reformulated Gasolines were assessed over 60,000 miles. For additional comparison, testing was also conducted with catalysts from six 1994 Toyota Camry vehicles, which had previously undergone 110,000 miles of controlled mileage accumulation.

A statistically designed fleet test was conducted to evaluate the effects of intake valve and combustion chamber deposits on vehicle performance and regulated tailpipe exhaust emissions. This test was run in twenty 1994 vehicles, powered by Ford 2.3L Dual Spark Plug engines. These vehicles were driven by trained drivers for 40,255 km (25,000 miles) on a specific test route to promote intake valve deposits. The test matrix included both reformulated and conventional gasolines, and three different gasoline additive technologies. Also evaluated were the deposit effects on octane requirement increase. In addition, an attempt was made to correlate the intake valve deposits from the field test with the current BMW 318i and proposed Ford 2.3L intake valve deposit tests. This study showed significantly higher HC and CO emissions with the untreated base fuel. A directional increase in NOx emissions was observed with increased combustion chamber deposits.