What Happens When Diesel Fuel Is Put Into a Gas Tank?

Diesel Fuel Basics

  • Most diesel fuel comes from crude oil. This oil is then refined through a process called fractional distillation, which separates the actual fuel from the less burnable and more viscous parts of the crude. However, crude isn't the only source for diesel fuel. It is also possible to use various types of oils, such as vegetable oil and peanut oil, as a type of fuel for a diesel engine. These types of diesel are better for the environment and better for the car's engine.

The Gas Tank

  • Gas tanks of cars are almost universally behind a rear tire. All have to fill a few criteria. They must first be able to store gas. This means they must minimize potential evaporation of the gas, while still allowing excess evaporation out, so the contents of the tank aren't pressurized. They need to be safely accessible for refueling. They must have a gauge inside them to give a readout to a driver of how much gas is left in the tank. They must also have a pumping system which moves the gas from the tank to the car's engine itself.

Diesel Fuel in a Gas Tank

  • There are two possible results from this scenario. If the diesel fuel is put into a gas tank that is connected to a non-diesel engine, the engine will be damaged and need repair because it works through spark ignition, a different combustion system than a diesel engine. When the diesel fuel is placed into a diesel engine's gas tank, it is used to power the engine when it is turned on. When the engine is turned on, the combustion chamber lets air in and then that air is pressurized until it reaches around 1,000 degrees F. At this point, the diesel fuel is injected and this fuel vaporizes, due to the heat. The fuel vapor then ignites due to the heat and forces pistons to move the crankshaft. This is the power behind the engine.