The effects of temperature and fuel volatility on vehicle evaporative emissions

21 Jan 1990

Matched pairs of European vehicles with and without carbon canister evaporative emission control systems have been tested to establish gasoline evaporative emissions, including running losses.Measurements were made over a range of ambient temperatures, fuel volatilities and different driving patterns.The uncontrolled vehicles exhibited gasoline vapour emissions which increase progressively with ambient temperature and fuel volatility. A 1°C change in ambient temperature was found to have the same effect on evaporative emissions as a 3.8 kPa change infuel RVP Carbon canisters were found to provide effective control of gasoline vapour emissions, capable of reducing total daily emissions by around 95%. Large reductions in benzene emissions were achieved by the canisters, in line with the total emissions.Reducing fuel volatility had no significant effect on emissions from the canister equipped vehicles