Exhaust Emission from Passenger Cars During Engine Cold Start and Warm-Up

An increased of carbon monoxide and hydrocarbons emissions from gasoline engines in ambient temperatures at or below 0°C is a key issue, not only in Scandinavia or northern parts of the USA and Canada, but also in countries of Central and Eastern Europe. It is typical of Poland and neighbouring countries that for six to seven months (from October to April) air temperature fails to about 0°C at night, while in winter months this temperature often fails below -10 to even -20°C. Due to this, in these countries the cars are started in the morning when the engine and all other parts of the car are considerably cool. This paper presents a special climatic conditions in view of their effect on the actual exhaust emission from a car with SI engine and results of emission tests for such gaseous pollutants as CO, HC and NO_x, achieved during tests performed on a chassis dynamometer according to ECE and FTP 75 cycles. These tests were performed with car conditioned in temperatures appropriate for such tests, i.e. about 22 to 23°C and lower: about 0°C, -3°C, -7°C, down to -15°C and also for a car fully warmed for comparative reasons. It has been found that when the temperature of car conditioning drops, a significant increase in emission of CO and HC is observed during engine warm-up.