[3352G0]

Is it true...friend who is a mechanic said to leave the tank at least half full at all times to avoid wear and tear on fuel pump. I've always let it drain to almost empty but maybe not on the E92?

[MikeCCrutchfield]

Originally Posted by 3352G0

Is it true...friend who is a mechanic said to leave the tank at least half full at all times to avoid wear and tear on fuel pump. I've always let it drain to almost empty but maybe not on the E92?

Depends on the vehicle...I had a friend who had an early 90's Jeep Cherokee and the fuel pump was in the tank. He said he had to keep his car above a 1/4 tank because otherwise the pumps were prone to failure. That said.....the car's need to be designed to use the fuel range volume of the tank, otherwise, you are significantly impacting the range.

[achien]

Originally Posted by 3352G0

Is it true...friend who is a mechanic said to leave the tank at least half full at all times to avoid wear and tear on fuel pump. I've always let it drain to almost empty but maybe not on the E92?

Do you have to suck harder if you are drinking from the straw of the glass/can that is almost empty, or full?

[drexplode]

Originally Posted by 3352G0

Is it true...friend who is a mechanic said to leave the tank at least half full at all times to avoid wear and tear on fuel pump. I've always let it drain to almost empty but maybe not on the E92?

Ummm what?

Tell your mechanic he doesnt understand fuel systems. Old school days, fuel delivery modules (fuel pump) were pumps on a stick with a simple suction filter/strainer attached.

Now-a-days with electronic (PWM) returnless fuel systems (like our BMWs), the module is designed to draw fuel from the bottom of the fuel tank, send it through a life-time filter and then dump it into a reservoir (aka bucket). The fuel pump will deliver fuel from the bucket (i.e. clean fuel), send it through the filter again, and then send what is required to the engine.

The only time the fuel pump doesn’t prime with filtered fuel is during green prime (1st engine start ever). Anytime after that the fuel pump should only see filtered fuel. Unless you completely empty the system...which is usually not very common.

To ruin a fuel pump: run your car out of fuel repeatedly.

[RiXst3r]

the fuel pump is not failing... its the direct injection HIGH PRESSURE fuel pump that is failing... other cars without D/I dont have this pump

[Cadillac Johnson]

There is a benefit to this, IF the pump is in the tank.

Basically the gas helps to keep the pump cooler.

cooler pump = longer life