Fuel pump cooling, the end all be all argument.

My 2 cents, since I personally believe the fuel pump cooling failure from running the tank low is an urban legend. I put it in the same category as engines needing back pressure, otherwise you'll end up with burnt valves. 

1) Running out of fuel and then pump failure in the near future: Running dry is a lot different than running the tank low. Running dry is something a lot of pump seals and bearings don't like to do and the lack of lubrication is a different failure mode than heat. 

2) Running fuel level low: Running the tank down to E should be within the design parameters, unless someone has a manual that says not to dry below 1/4 tank, but I can't say I've ever seen or heard of that in a manual. 

3) Warranty: anyone ever see a manufacture warranty have exclusions due to running a fuel pump low? The pump should be able to handle the warranty period (3/36, 5/50, 10/100) even if run regularly in the bottom 1/4 of the fuel tank. 
 

I only have anecdotal evidence. My '02 Avalanche fuel pump overheated and died. It was obvious from the melted wire insulation and shorting out, blowing the fuse. It has 6 gallons remaining when it hits E. No idea how submerged it is.

It's the only pump of mine (20-ish vehicles) that has ever failed, I fill up at 1/4 usually. 

Never run your tank down to E it will suck the dirt out of the bottom of the tank, it will plug your filter then the pump works harder and dies.   You see when your tank is full it pulls from the top.  Open up a gas tank and you will see a little float in there, that is the sensor that tells the pump where to suck from.  The trick is to bend the arm on that float so it can't ever get to the bottom that way you all ways pull clean fuel.

Fuel is self cooling and does cool the pump, it cools even better once you introduce air.  Put your hand in a bucket of hot fuel, it feels hot right?  Not take it out and feel how cool your hand gets, that's the self cooling effect.   So when the pump starts sucking a little air when your run out of gas it just cools the pump better.

Arguing in the internet is my full time job, that's why I'm so good at it.

In reply to akylekoz :

Water is even better at cooling, that's why I always add about half a gallon of H2O at each fill-up. Also increases my MPG by 7.34522%. Big oil doesn't want us to know about the water hack. Follow me for more money-cos... uh.... saving ideas.

In reply to 90BuickCentury :

Good idea that must by what the E-15 to E-85 mixtures are for...to mix with the water.   Probably reduces emissions too. 

Based on experience "E" in a uHaul truly means EMPTY!

I think the fuel pump cooling story is an excuse created by GM fanboys to excuse their E36 M3 fuel pumps in the 80's, 90's, 00's, and so on.

In reply to akylekoz :

If you bend the arm the other way the gauge will never get to E ever again. Problem solved!

I was really hoping this thread was going to be about jaguars 

Robbie (Forum Supporter) said:

I was really hoping this thread was going to be about jaguars 

Sssstooooooppppppppp!!!!

I don't ever run the tank past 1/4 left just because OKC can have wildly varying traffic and I don't want to end up on the highway, on the shoulder, out of fuel if I get caught in a traffic jam. 

Side note: My '88 300ZX I had in high school and first two years of college had a 20+ gallon tank. My car had the digital dash, so it would show the tank as empty, and then another little area underneath would pop showing you had 5, 4, 3, 2, 1 gallons actually left. Seems like a weird design. 

z31maniac said:

I don't ever run the tank past 1/4 left just because OKC can have wildly varying traffic and I don't want to end up on the highway, on the shoulder, out of fuel if I get caught in a traffic jam. 

 

Side note: My '88 300ZX I had in high school and first two years of college had a 20+ gallon tank. My car had the digital dash, so it would show the tank as empty, and then another little area underneath would pop showing you had 5, 4, 3, 2, 1 gallons actually left. Seems like a weird design. 

Friend of mine had an ironing board Supra in the mid 80's.  It had the same gas gauge, and on a road trip, he ran out of gas exactly when the little gauge hit zero.  A mile from the next town.

Walking was involved.