Fuel pumps are responsible for delivering fuel from the fuel tank, that is usually located in the rear of the vehicle, to the fuel rail or carburettor, that is generally located atop the engine under the bonnet. In older pre-fuel injection vehicles dating from the 1980s and older this is usually performed by a mechanical fuel pump, while in most later vehicles manufactured after the introduction of fuel injection this role is fulfilled by an electric fuel pump. A correctly performing fuel pump is critical for maintaining a minimum safe pressure and flow for the engine to operate efficiently throughout it's rev range, and a failed or faulty fuel pump can result in reduced performance, failure to start or potentially lead to catastrophic engine failure.