Fuel supply system includes the entire system necessary to transport the fuel to the engine. There are differences between the fuel systems of diesel and gasoline vehicles. In diesel engines fuel-air mixture is produced in the combustion chamber and in classic gasoline engines in the carburettor. In addition, modern cars now use direct injection in both systems.

The fuel system is equipped with an electric pump to move the fuel. The pump pumps the fuel out the tank and pumps it into the fuel filter. The filter removes impurities from the fuel. Then there is a carburettor or direct injection. If the system is leaking, the fuel drips on the ground. If there are other problems in the fuel supply system, it can lead to complete power loss.