Diesel fuel is a mixture of liquid hydrocarbons obtained with the fractional distillation of crude oil and use as fuel for diesel engines, heating and for the production of electrical energy.

When used as fuel for diesel engines, it is injected into the combustion chamber where, on reaching certain values of temperature and pressure, it ignites on contact with air.

Diesel fuel has to satisfy certain requisites to be sold, and these are defined at the European level by the reference standard EN 590 issued by the CEN and applied in Italy as UNI EN 590.

Diesel fuel for motor vehicles complies with legislative decree no. 55 dated 31 March 2011, implementing Directive 2009/30/EC, and can be blended with biodiesel.