Fuel Tank

Fuel tanks are manufactured to meet safety requirements established by the design engineers and to meet low weight requirements. Fuel tanks are made either of steel or high density polyethylene depending on the vehicle.

Steel = E321 E34, E38, E39
Polyethylene = E31, E36, E46

All vehicle fuel tanks contain the internal fuel pump(s). The now familiar saddle type fuel tank was initially introduced with the E31. The saddle tank provides a tunnel for the driveshaft but creates two separate low spots in the tank.







A Syphon jet is required with this type of tank to transfer fuel from the left hand side, linked to the fuel return line. As fuel moves through the return, the siphon jet creates a low pressure (suction) to pick up fuel from the left hand side of the tank an transfer it to the right hand side at the fuel pick up.