In this study, the influence of gasoline composition on exhaust emissions has been evaluated using three gasoline vehicles. Although the vehicles were obtained within Europe, each is representative of models to be found in Asian markets. Two of the vehicles were current Euro 4 certification, while the third was of Euro 2 certification equivalent to that available in specific Asian markets.
Fuel effects studied included aromatics, olefins and benzene content. Other fuel properties were held constant within the normal constraints of blending when using realistic gasoline components. An orthogonal matrix of eight fuels was blended to evaluate these properties over the ranges: Aromatics (excluding benzene) 34% to 49%, olefins 18% to 25% and benzene 1% to 5%.
All fuels were tested in all three cars driving the current legislative NEDC cycle, using a randomised block design with at least 3 repeats on each fuel/vehicle combination. This paper will describe the results obtained and compare the fuel effects in context with similar test programmes, demonstrating the low sensitivity of exhaust emissions from modern vehicles to these fuel properties.