Approval tests and evaluation of emission properties of vehicle

Operation of vehicles equipped with combustion engines is a source of pollution. That is why the emissions from this source are restricted. The emissions reduction system consists of several steps, whose basic component is a typeapproval of vehicle in terms of emissions level and admission to the registration of vehicles that meets the requirements for emissions. It is assumed, that the gradual reduction of emissions limits will improve the emission properties of the vehicles, and gradual withdrawal of used vehicles, will reduce of emissions growth. The basis for issuing opinions on a vehicle's exhaust emissions is the measurement of emissions performed in the laboratory on a chassis dynamometer in reproducible conditions of preparing the vehicle for testing, test replication, fuel for the engine, and the procedure for collecting the exhaust gas analysis. Motor Transport Institute conducts the type approval tests, as well as the research on emissions from vehicles in the real traffic conditions, which are used to determine the actual emission from the vehicle population. Emission tests for applications, that go beyond the application of type approval show, that there are vehicles whose emissions in operation is substantially different from the emissions measured during type approval. It is a natural phenomenon in the case of used vehicles and vehicles with engine malfunctions or exhaust aftertreatment system defect. However, there are vehicles whose emissions under specific operating traffic conditions are significantly different from the values obtained in the course of type approval tests, despite the good properties of emission measured under the conditions provided by the type-approval procedure. The article discusses the results of the emissions from vehicles, obtained in the tests used to determine the emission factors for vehicles used in real traffic conditions, thus taking into account emissions from vehicles, made under different conditions than the type approval tests, which show that, in terms of driving cycles, which are not covered by the emission test procedure, can multiply and exceed the approved values.. This is particularly true for modern diesel engines