Diesel Oil is a complex mixture of Hydro Carbons. It is a brown coloured oily liquid with pungent smell. MPRL domestically mainly markets two grades of HSD namely BS-III & BS-IV.The main difference between BS-III and BS-IV in the sulphur content, i.e. for BS-III 350 ppm and BS-IV 50 ppm.

Diesel engines are used in cars, motorcycles, boats and locomotives. Automotive diesel fuel serves to power trains, buses, trucks, and automobiles, to run construction, petroleum drilling and other off-road equipment and to be the prime mover in a wide range of power generation & pumping applications. The diesel engine is high compression, self-ignition engine. Fuel is ignited by the heat of high compression. HSD is normally used as a fuel in medium and high speed compression ignition engines (operating above 750 rpm) in commercial vehicles, stationary diesel engines, locomotives and pumps etc.

BS-IV grade is used in certain specified markets in India which includes metros and other few cities. For all other parts in India BS-III is used. MRPL manufactures both Euro IV and Euro III grades to cater the market.