Automotive Gas Oil (AGO) popularly known as diesel is a complex mixture of hydrocarbons produced by mixing fractions obtained from the distillation of crude oil with brand-specific additives to improve performance. Under normal conditions it is a liquid with a characteristic odour. Diesel is produced by blending straight-run middle distillates (minimum 40%) with varying proportions of straight-run gas oil, light vacuum distillates, light thermally-cracked distillates and light catalytically-cracked distillates.
AGO (diesel) is mainly used as a fuel for road vehicles, although other forms of transport (such as ships and trains) and electricity generators also use certain types of diesel. It is generally used as fuel for heavy duty engines.