An Evaluation of Automobile Total Hydrocarbon Emissions

Practical and simple procedures have been developed to reliably estimate the quantity and reactivity of automobile carburetor and gasoline tank evaporative emissions. These methods along with previously developed exhaust hydrocarbon emission procedures have been used to determine the effects of fuel volatility on the quantity and smog forming potential, that is, weight of emissions multiplied by reactivity, of automobile total hydrocarbon emissions. Results on two different 1965 automobiles operated under average conditions showed that increasing fuel volatility decreased the smog forming potential of the total emissions from both automobiles.