The internal combustion engine is also a source of chemical and sound pollution that harms humans and the environment. Chemical pollution is due to substances and chemical compounds that are found in the exhaust gases of motor vehicles. Along with the evolution of technology, the pollution norms have also evolved, becoming more and more restrictive. Reducing the emissions produced by the internal combustion engines of motor vehicles is the most important goal of the manufacturers at the present time. The increase in the number of motor vehicles has led to the need to improve the ecological performance of the engines that equip them, in order not to increase air pollution substantially. In developed countries, environmental pollution has reached frightening limits. In connection with the fact that toxic substances migrate through the air from one country to another and even from one continent to another, there is irreversible pollution of water, air and soil, which is not only local. From year to year, the expenses invested in combating the consequences of the ecological impact increase. The main role in atmospheric pollution is played by emissions from road traffic, thermal power plants and enterprises. In the majority of developed countries, the contribution to the total content of atmospheric pollutants is in the sphere of car transport approx. 60%, in industry 17%, in the energy industry 14%, in waste incineration 9%. In big cities, cars are the main source of pollution with carbon monoxide, hydrocarbons, nitrogen oxides, aldehydes, soot, etc