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This paper presents the results of a three city survey designed to determine the relative frequency of illumination of vehicle on-board diagnostic (OBD) malfunction indicator lights (MIL) on 2001 and later model year vehicles. The survey was conducted in a Canadian market, Regina, and two U.S. markets, Minneapolis and Denver, to assess claims that the presence of methycyclopentadienyl manganese tricarbonyl (MMT®) in gasoline causes the failure of technology necessary to meet stringent Tier 2 emission standards applicable in North America. The results of the survey do not support the claim that MMT® is incompatible with the effective functioning of the advanced vehicle emission technology necessary to meet Tier 2 emission standards. The results substantiate that the performance of the most advanced vehicles operating on gasoline containing MMT® is not materially different from the performance of comparable vehicles operating on gasoline that does not contain MMT®.

Mobile source emissions standards are becoming more stringent and particulate emissions from gasoline direct injection (GDI) engines represent a particular challenge. Gasoline particulate filter (GPF) is deemed as one possible technical solution for particulate emissions reduction. In this work, a study was conducted on eight formulations of lubricants to determine their effect on GDI engine particulate emissions and GPF performance. Accelerated ash loading tests were conducted on a 2.4L GDI engine with engine oil injection in gasoline fuel by 2%. The matrix of eight formulations was designed with changing levels of sulfated ash (SASH) level, Zinc dialkyldithiophosphates (ZDDP) level and detergent type. Comprehensive evaluations of particulates included mass, number, size distribution, composition, morphology and soot oxidation properties. GPF performance was assessed through filtration efficiency, back pressure and morphology.

Since the introduction of the catalytic converter, some automobile manufacturers have questioned whether the converter is compatible with the use of the gasoline fuel additive MMT®. Concerns have generally revolved around possible interactions between combustion products of MMT® (i.e., manganese containing compounds) and catalytic converters. In particular, concern has been raised over the possibility that MMT® combustion products physically “plug” the catalyst and cause catalyst failure, where plugging refers to blockage of contiguous pores at the catalyst inlet face or within the body of the converter. In modern vehicles this could result in the illumination of the malfunction indicator light (MIL) due to storing of an on-board diagnostic (OBD) failure code pertaining to catalyst operation or failure of a vehicle inspection and maintenance (I/M) test.

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.