Fuel pumps/ empty gas tanks

Dear Ray and Tom,

I read your article regarding the empty fuel tank and it’s related damage to the car.

I know a few very good mechanics who all agree that running tank low on fuel is the number one reason the fuel pump fails. It overheats due to lack of coolant.

They all state they have never replaced a fuel pump when the customer, like me, keeps at least 1/4 tank of fuel at all times.

I agree with you guys and love your article and show. I think you’re wrong telling folks it’s OK to run your tank low.

Respectfully, Phil

If running your tank low (or even empty) killed your fuel pump I would be replacing them by the bushel basket. I have never seen any technical material from eiher the manufacture of the car or the manufacture of the pump confirming what you say about fuel pumps.

Think of what you are saying, you are saying the last 1/4 of the tank is unusable or usable only at the risk of pump damage. Look around for something from a pump manufacture or a auto manufacture that puts out something about this subject (even if it is biased) Lets look the info over.

Low and empty are 2 different things

Low and empty are 2 different things
Sure, but since the post suggests that running the tank LOW causes damage, what are you trying to get at?

just read the piece about runing the tank low and damage, I have seen it more than once. Todays fuel is incredibly DIRTY, DO NOT run the tanks low even with the newer plastic tanks fuel is dirty from delivery line to bulk storage. I am a retired fuel transport driver and I have seen it first hand, the trucks are clean,its the manufacture and related distibution lines are very old and are sluffing off, your fuel comes to you full of rust,this is fouling filters and ruining pumps, change filters often

The last sentence states as follows: I think you’re wrong telling folks it’s OK to run your tank low.

Im getting at low and empty are 2 different things. Low wont hurt your fuel pump…empty will

Apparently, “yesterday’s” fuel wasn’t exactly clean either!

On my '74 Volvo (purchased new and maintained better than the mfr specified), the Bosch fuel pumps could be depended on to burn out approximately every 12-13 months, and these pumps were not located inside the gas tank. My only explanation (other than the fact that the car was unmitigated crap) is that the gasoline circa '74-'81 was incredibly dirty or the Bosch fuel pumps were as crappy as the rest of that Volvo.

Can’t anyone come up with any type of published article about this (anything but a story from Yahoo that is, I think we have all agreeded not to accept automotive information from Yahoo).I am open to looking this over. I must have changed 200 fuel filters over the last 35 years and I can think of probably 2 that I actually saw paticulate matter run out of when emptied. Sure I can testify to seeing a small amount of rust colored material at the bottom of gas tanks (noticed when changing fuel filters). I think the majority of fuel pumps I have changed over the years went bad due to design errors (ruptured diphrams on mechanical pumps don’t count). Fuel pump failure did happen on CIS cars like VDC describes but never on one of my CIS cars.

Im getting at low and empty are 2 different things. Low wont hurt your fuel pump..empty will
I guess I thought you were responding to the first response on here. (I don't like the way this forum shows responses, which is why I try to quote at least a little from whatever I'm responding to.) I don't doubt that running a tank completely empty (repeatedly) could cause a problem, but just running the tank low is going to cause fuel pump problems? I'm not buying it. And needing to keep at least a quarter tank in it? I don't think so. As far as dirty fuel being a concern - I would expect to see problems in other areas before a failing fuel pump due to dirty fuel.

It overheats due to lack of coolant.
Looking for a fuel pump with coolant, unless you mean the flow of fuel acts as a coolant.

If some cars get below an eighth of a tank, the engine will sputter or stall when you try to navigate hills. Some you can run until the warning light comes on and beyond. Try to fill up when the tank gets down to a quarter and you’ll never have a problem caused by low fuel.

Sometimes it just that on payday you have just enough gas in the tank to make it to the bank and then go fill up. It would have been nice to always have a “fund” to turn to but after tapping the emergency money till it was dry it was just week to week after that. I really don’t feel so lonely because there are plenty others looking for change to get a few bucks in the tank just to get too work on payday (that is if they have a job to worry about getting too at all).

Phil Greene is right.

I’ve provided a link to a “manual” provided by a manufacturer of fuel pumps. Under item 4 it specifically talks to the issue of routinely running the fuel tank low amd potential damage to the pump, as well as the need by the pump for fuel to cooling and lubrication.


Well I did say I would look at any info. This link says CAN lead to failure but also says “a thorough cleaning of the tank should accompany every pump replacement” Yeah right, that gets done every time.How about something from a vehicle manufacture? that would “close” the subject for sure.

You must remember these manufactures will point to anything but themselves as to why a pump failed.I found a link from an AC component manufacture that implies drier/accumulator replacement should be a service item, no one liked that at all.

Even those of us with ah herculean appetites for the diverse and the bizarre. Even those of us who ah, who’ve shown an aptitude to ah…to aaaaaahhh…fight the good fight, and stay the good long battle. Even those of us can get tired. And your boy is tired after thirty consecutive nights…I’m a pro. That’s what pros do. I’m a PRO-fessional. Look it up in the book.

Oh-kay…That’s what we do, we’re pros. We’re never rude, and we don’t cop out. We don’t tell you that we’re ill, or that we’re looking for the farmhouse in the middle of the desert, or that we’re parched. We don’t tell you that maybe the check didn’t come through this month, or where the hell does it go anyway, if you’re a guy who’s left 16 forwarding addresses. Oh-kay. The club? No, don’t worry about the club, worry about maybe…JACKY might worry…NAH, don’t worry. Okay, just cool it…Life is a breeze. 'Course some breezes, as you know, are a hundred and ten miles an hour and get promoted up to hurricanes, I just thought I’d pass that along.

Well, let’s put it this way: since the fuel pump manufacturer says it CAN lead to fuel pump failure, and the rational seems logical, why not follow the recommendation? It doesn’t cost any more to keep the top half of the tank full than it does to keep the bottom half full…or to let it keep running low and refilling it when the warning light illuminates.

Keeping the top half full has other benefits. It prevents running out unexpectedly should you end up in stopped traffic due to a blizzard (happens often on the Everett Turnpike) or due to an accident ahead, and it effectively limits the odds of having problems due to bad gas by mixing any bad gas you might get with the good gas already in the tank.

There’s no “downside” to keeping the top half full. Only “upsides”.

The gas itself acts as a coolant.

It doesn't cost any more to keep the top half of the tank full than it does to keep the bottom half full...There's no "downside" to keeping the top half full. Only "upsides".
It costs you 100% more number of times stopping to fill up with fuel. And, it you wanted to get real nitpicky, I suppose it could be argued that by never allowing the tank to go more than half empty, you're keeping the average amount of fuel carried higher than if you run it nearly empty before filling up, thereby carrying an extra amount of weight around all the time, and decreasing your mileage. Maybe not significantly, but between that and the extra time spent pulling in to fill up more often, I don't think it can be said that there's no cost, or other downside, to limiting yourself to no less than half a tank.

The cost I was clearly referring to was the monetary cost. that’s determined by your car’s mileage, your driving habits, and your driving environment, and remains the same no matter whether you stop at every 1/2 tank to fill up or wait until the tank is empty.

I’ll grant you that the extra 1/2 tank of gas has weight to pull around, typically about 50 pounds, but the extra gas to pull it around is pretty tiny.

But i stand by my post. Not routinely running the tank low is prudent, and the gas pump manufacturer’s warning should be considered prudent to follow and the cost is too small to effectively measure, small enough that for practical purposes i’ll still maintain that it costs no more to keep the top half of the tank full than to routinely let the tank run low.