[HokieBill]

I think that the assertion that a fuel pump will overheat if the fuel level is low is an "old wives tale". The fuel pump is cooled by the fuel that flows through it, not by being immersed. And remember that the pump flows FAR in excess of what is being used, with the remainder being returned to the tank continuously. The heat sink theory is baloney, too. With the fuel sloshing around the vast expanse of the tank, it will cool easily.

As far as driving past the "0" miles display, I've driven at least 50 miles past 0, and still only filled up 11.7 gallons. So even then, there was plenty of gas left to "cool" the pump

Ditto to Reddog99's logic. If (and I think that's a big if) the pump needs cooling, the fuel sloshing around and the fuel traveling to and from the engine will do that. On the other hand I do think it is a really bad idea to actually run out of gas. That can't be good for either the pump or injectors since the fuel is bound to provide some amount of lubrication.

I do not know why the pump is in the tank but I would guess it has to do with easier self-priming rather than cooling. Self-priming would not be a problem on a motorcycle since the pump is below the tank.

 

[Norm201]

This should settle the argument and I stand corrected

Today's fuel pumps are immersed in the tank for a good reason and need fuel surrounding it. Two main reasons. Prevent vapor lock and prevent fire hazard by virtue of the fact that liquid fuel is not combustible.
Rather than paraphrase I'll "lift" the article from

Fuel pump - Wikipedia, the free encyclopedia

In many modern cars the fuel pump is usually electric and located inside the fuel tank. The pump creates positive pressure in the fuel lines, pushing the gasoline to the engine. The higher gasoline pressure raises the boiling point. Placing the pump in the tank puts the component least likely to handle gasoline vapor well (the pump itself) farthest from the engine, submersed in cool liquid. Another benefit to placing the pump inside the tank is that it is less likely to start a fire. Though electrical components (such as a fuel pump) can spark and ignite fuel vapors, liquid fuel will not explode (see explosive limit) and therefore submerging the pump in the tank is one of the safest places to put it. In most cars, the fuel pump delivers a constant flow of gasoline to the engine; fuel not used is returned to the tank. This further reduces the chance of the fuel boiling, since it is never kept close to the hot engine for too long.
The ignition switch does not carry the power to the fuel pump;....

I previously stated that Tom & Ray of Car Talk said its not good to run your tank to empty. I stand corrected. They don't seem to think it makes a difference. See

Is it really OK to let your gas tank run down to empty? - NWautos

Also from
Running on Empty - ABC News

By JOHN STOSSEL
June 5, 2008


So why do cars say "empty" when there's still gas left? Ford said it's about providing a "comfort zone" for the driver -- you don't want to have the light go on and all of a sudden, you're dry. GM said that customers in the United States want that reserve, and they provide it. Chrysler said some drivers, German customers, for example, want to know exactly how much gas is in the tank, but Americans like to have a buffer.

However, do a Google search titled "is it safe to run a gas tank to empty" and you will see testimony from many saying its not a good idea.

I'll continue to error on the side of safety. Especially since a fuel pump can cost between $400 and $1000 repair. Is it worth it?

 

[HokieBill]

I bow to your greatness Norm201. Great investigative work.

 

[Norm201]

I bow to your greatness Norm201. Great investigative work.

Thank you kind sir.

 

[Reddog99]

Ditto to Reddog99's logic. ...... That can't be good for either the pump or injectors since the fuel is bound to provide some amount of lubrication.

Pump (lack of) lubrication won't enter into the equation either. Since the engine will not run without fuel, and the pump will not run with the engine stopped, then the pump will not run if it runs out of gas....

 

[psi chick]

i have had a fuel pump go on me due to running it dry. it was because the pump was straining so hard to get enough fuel to maintain pressure and it burnt out. it was completely my fault (i knew better than to let it get that low), and not something that i would expect to happen on a typical, non-modified car. i only mention it because it IS possible for this to happen. on the average car though, i wouldn't worry about it.

i never let my tank get that low though, just because i don't want to run out of gas. i'm not concerned at all that it's going to burn the pump. and if it does end up burning out the pump, it will be long after i've gotten rid of the car lol

 

[iamz]

Thanks for posting that Norm. I think you're being overly cautious but, to each their own. I'll continue filling up when there is about a gallon left and know that I'm probably well within the engineered design spec of safety relative to the pump.

 

[Fiesta33460]

Getting back to the thread... I routinely run 10-15 miles past the "0 DTE" reading. That whole measurement is suspect since, in my car, the number ALWAYS drops from about "17 DTE" to zero in 2-3 miles. Where'd those missing 15 go?? And I still can only get 10.5 or so gallons in.