Driving on high inclines

[CFI]

I recently did some mountain driving which included driving up 15% grades. This got me wondering.

I’m currently using the GM style pump, which has no external fuel pickup hose. So I’m assuming it can only pump fuel that is in its immediate vicinity. Since the pump sits very close to the front of the tank, how many gallons, at a minimum, would you need to have in the tank in order to not starve the pump when driving up a 15% grade?

[Michael]

I recently did some mountain driving which included driving up 15% grades. This got me wondering.

I’m currently using the GM style pump, which has no external fuel pickup hose. So I’m assuming it can only pump fuel that is in its immediate vicinity. Since the pump sits very close to the front of the tank, how many gallons, at a minimum, would you need to have in the tank in order to not starve the pump when driving up a 15% grade?

The only issue I have with the new pump is our tanks are not designed for them. The new pumps ideally should sit in a cavity or low spot on the tank since the pick up is internal. It's just a necessary evil though. I consider 1/4 tank being the equivalent to the low fuel light, especailly considering my location. Someone in FL might go to the 1/8 mark.

[Bitsyncmaster]

I've always wondered the same. I not sure if tanks in new cars have a sump where the pump sits. I don't see any sump looking at the bottom of new cars.

[CFI]

I've always wondered the same. I not sure if tanks in new cars have a sump where the pump sits. I don't see any sump looking at the bottom of new cars.

Lol, I’m glad I’m not the only one. It’s been a while since I’ve been in the car biz, but you’d think an internal pump would be better suited for the back of a fuel tank to prevent starvation going up hills.

[Bitsyncmaster]

Lol, I’m glad I’m not the only one. It’s been a while since I’ve been in the car biz, but you’d think an internal pump would be better suited for the back of a fuel tank to prevent starvation going up hills.

I agree because going down hill your not using much gas.