Conventional transportation fuels are diesel, fuel oil, gasoline, kerosene, oxygenated gasoline, and reformulated gasoline.

Diesel

Diesel fuel is a complex mixture of hydrocarbons distilled from petroleum. It is composed mainly of compounds that will auto-ignite from the heat of compression in a diesel engine, which has no spark plugs. Diesel fuel is used mainly by heavy-duty and medium-duty trucks, construction equipment, locomotives, and marine and stationary engines.

Figure 6 Vintage diesel truck