[header] How to choose the right fuel for your car [title] Use diesel fuel if your vehicle is designed for it. [step] Engines designed to run on diesel fuel operate differently than those designed to run on regular gasoline. Diesel engines do not use spark plugs, and instead rely on the compression of the air and fuel to ignite the mixture alone. 
Because of this, diesel fuel is less stable and cannot be used in engines designed for gasoline. Diesel vehicles usually have clear " diesel only " markings on the inside of their fuel doors, and traditional gas pumps won't fit in their filler necks.