Reduced particulate emissions with reformulated gasoline

Exhaust emissions from cars using reformulated gasoline (RFG) that meets European 2005 regulations for gasoline quality were compared to the emissions from cars using gasoline that meets European 2000 regulations (EU2000). Methyl Tertiary Butyl Ether (MTBE) and Tertiary Amyl Methyl Ether (TAME) were used as oxygenates in the reformulated gasoline. The EU2000 gasoline contained no oxygen.

Regulated, particulate and PAH exhaust emissions were measured at 22°C for 7 cars and at -7°C for 5 cars using the European MVEG cycle for year 2000 (ECE+EUDC). One of the cars was equipped with a lean burn engine, one with a direct injection engine and one was a carburetor equipped car without a catalytic converter. All other cars were equipped with multi point port fuel injection and a catalytic converter. Mutagenic activity of particulate mass was evaluated using the Ames test.

Particulate emissions of reformulated gasoline were decreased on average by 30% at 22°C and 40% at -7°C compared to EU2000 gasoline. This observation may be significant as harmful health effects of particulates have recently been under discussion in many countries. Particulate emissions were remarkably higher at -7°C than at 22°C. The amount of polynuclear aromatic hydrocarbons (PAHs) in particulates were significantly lower when reformulated gasoline was used. The effect was similar both with the cars equipped with catalytic converters and with the car without a converter. The tentative mutagenicity tests of particulate mass showed lower response for reformulated gasoline than for EU2000 gasoline.

Emissions of total hydrocarbons and oxides of nitrogen were also reduced at both temperatures when reformulated gasoline was used instead of EU2000 gasoline.