Keep the level up - Your fuel pump will last longer!

[Low drag - High speed]

Another good reason to keep her topped up is fuel weight. The pressure at the bottom of the tank is higher when a few more gallons are sitting on top and it helps push the fuel through the pump, assisting the turbine and reducing wear on the pump. Less important than the cooling, but another small part of pump life and engine efficiency.

As for wires inside the tank ... as long as the connectors are tight there is no fire danger, even when the level is low. Electricity is not the danger, but rather the spark it generates when loose parts brush together. No spark ... no explosion. And previous posts are correct about oxygen. Gasoline will only burn on the surface, which is why it's turned into a vapor for internal-combustion engines. Fine droplets burn very well, but standing liquid will nly burn on the top and will not explode. If other factors are added, like a bomb, a collision that scatters it in the air, or a tracer bullet that causes it to expand and then lights it, you have an explosion ... but not just by itself. And don't forget the spark ......

 

[Louis Bartay]

Another good reason to keep her topped up is fuel weight. The pressure at the bottom of the tank is higher when a few more gallons are sitting on top and it helps push the fuel through the pump, assisting the turbine and reducing wear on the pump. Less important than the cooling, but another small part of pump life and engine efficiency.

I never thought of that. I can see that it would help. The only down side is the weight of the gasoline hurts the HP per weight ratio a little.But I would rather protect the pump as I do not take my LT4 to the Drag races to race. I have the motorcycles for that.

 

[Boeingdriver]

Low fuel kills pumps....

Chevrolet and GMC trucks use the same submerged pump design as Corvettes. From posters on another forum, I knew my '91 GMC Safari van was due for a failure at 100k or more in normal usage. Other posters who regularly ran their tanks almost dry were replacing pumps on 30k intervals and couldn't figure out why.

The tank has to be dropped to replace the pump in a van and it's a $600 job in a shop or out on the interstate somewhere. I set aside a weekend and replaced mine at 130k even though it was working fine. It was a rough, dirty job but for $45 (the OE Delco pump) and a few hours of wrestling with a dirty tank on my abs, I don't have to worry about it letting me down.

And after you've changed one, you'll never run the tank low again.

Boeingdriver

 

[Low drag - High speed]

Man ... you sure got that right. I had a couple of the 80s Caddy Eldorados with the big long hoods and changed a couple fuel pumps over the years. I'd rather gargle the bum-squeezins' of 30 skunks than do that again.

 

[brimis]

Its important to keep the tank filled, if not condensation will form and you'll have water in the tank. When the tank is full air is kept out of the tank eliminating condensation.

Now, if I can only follow this policy!

 

[91savyvette]

Hi all, know i'm not around much..usually when a problem occurs.
Anywho... what are the symptoms of a Fuel pump going bad? My g/f called today saying her 90 was idling rough so I took it for a small test drive and yeah..rough idle and when cruising at one speed you can feel hesitation. At first i was thinking either Plugs/wires or fuel filter.
Sitting at 90K miles btw.

 

[Topless_Ruby]

Its important to keep the tank filled, if not condensation will form and you'll have water in the tank. When the tank is full air is kept out of the tank eliminating condensation.

Now, if I can only follow this policy!

This is the same reason aircraft are always stored away with full fuel tanks.
If your car sits for long periods of time with the tank partialy full the moisture will condense out of the air in the tank as it cools at night. The fuel will also will contract as it cools drawing more cool moist air into the tank. During the day it warms up and expands expelling the now drier air, ready to start the cycle over again the next night.