Effects of Fuel Volatility and Temperature on Vehicle Evaporative Emissions

Evaporative emission tests were performed on forty in-use late model passenger cars using different volatility fuels and varying temperatures. Results show that diurnal and hot soak emissions are quite sensitive to temperature, and also that the temperature sensitivity increases with the use of higher volatility fuels. Empirical models were developed to express diurnal and hot soak emissions as a function of fuel volatility and temperature.