| UN R83 Motor Vehicle Emissions | Motor Vehicle Emissions | Uniform Provisions Concerning the Approval of Vehicles with regard to the Emission of Pollutants According to Engine Fuel Requirements Together with R49, Regulation 83 addresses vehicle emissions. R83 covers emissions from all light vehicles (M1/N1) regardless of engine type and from heavier vehicles only if equipped with a gasoline engine. Under certain circumstances, R83 or R49 can apply to light vehicle CNG/LPG engines as well as to medium passenger and commercial vehicles (M2/N2) equipped with diesel engines. R83 also contains provisions specific to hybrid variations of the vehicles under its purview. Motor Vehicle Emissions Motor Vehicle Emissions UN Regulation No. 83 UN R83 | UNR | 83 |