Volatile organic compounds (VOCs) are a major component of pollutant emissions from gasoline-fuelled road transport. Beside the exhaust emissions originating from the combustion process, VOCs can arise from the vehicle’s fuel system (i.e. storage tank) and are called evaporative emissions. These occur as a result of fuel volatility combined with the variation in ambient temperature and temperature changes in the vehicle’s fuel system.
Read the full summary here: Impact of fuel ethers on evaporative emissions