Bad to wait until fuel light come on before refueling? (1 Viewer)

[Ryan Tsang]

Several of my friends got into a discussion about this topic. Is there any potential damage to a car to consistently wait until the fuel light comes on before refueling?

My stand is no. Correct me if I'm wrong....I believe the fuel pump works harder when the tank is empty. But there is still a safe reserve to get to a gas station. If there is any damage by waiting, automakers would have built-in a safety margin. That safety margin is the light, reminding you to go get gas.

Their daddy sez you should never go past 1/4 tank because it will suck in dirty contaminants into your engine. Is there any truth to this?

Any mechanics out there?

 

[Matt Stryker]

Is there any potential damage to a car to consistently wait until the fuel light comes on before refueling?

Until the light comes on? Depends on when the light comes on. My wifes old 88 Jetta had the worst system ever; the light came on after you ran out of gas...I only know this because she told me after having to coast into a BP.

Most cars now will auto-shutoff instead of running out, but on some earlier fuel-injected cars, you can do pretty serious damage to the injection system by driving it until its out. I know that Mercedes had warnings in their owners manuals in the 190 series cars for that specific reason. My wifes 2000 Jetta TDI has those warnings as well.

Never believe the automakers have your best interests in mind when they design anything. Or the guy that calibrates the sensor knows what hes doing. No, I'm not paranoid. And the first time you walk 3 miles to get gas because you ran out in 90 degree heat will be the last time you let it get below 1/4 tank without at least looking for a place to fill up. I never let my friend live that one down.

 

[Ted Lee]

but on some earlier fuel-injected cars, you can do pretty serious damage to the injection system by driving it until its out.

i dunno. i had an 89 rx-7. the owner's manual also said i should not run it dry as it could damage the fuel-injection system. but it seemed to run okay afterwards. i will say that the fuel-light sensor became less reliable. when it came on...i had to find a station fast.

in my current car (94 accord) i *NEVER* wait till the fuel light comes on...but i have a very good reason for that. simply put my fuel gauge isn't reliable anymore. i can completely fill it up, and the gauge may read half/full/empty. so...as soon as i get to about 275 miles on the odometer, it goes in for a full tank! i don't wanna be walkin' around like matt's friend....

 

[Patrick Sun]

I usually refill when it's about 1/8-1/16 of a tank left (judging by the tank gauge), or 300 miles. But that means knowing your car, and whether you've gotten some increased mileage from doing more highway driving than usual.

 

[Philip_G]

from what I understand two things are bad, #1 running the pump without much fuel, something about the pump uses fuel to cool itself and can burn out prematurely, and #2 sucking crud off the bottom of the tank, which I don't know about, the pickup is on the bottom anyway so I would think that would always be the case but who knows. It's just "what I've heard"

 

[Jason_Els]

1 running the pump without much fuel, something about the pump uses fuel to cool itself and can burn out prematurely,

Exactly what my mechanic said to me about my Saab 9000. Apparently the gas in the tank cools the fuel pump and if it gets too low then the fuel pump doesn't get cooled and you risk burn out; which is what happened to me though I never ran it very low. Saabs usually allow 2 gallons remaining before the light comes on.

I'm not all that happy that the fuel pump is cooled by gasoline as that tells me an electrical device is being exposed to a highly-flammable liquid. Now on my car it was fairly easy to take out but some cars have the fuel pump in[/in] the tank so that when it dies you have to swap out the whole gas tank and that's some fat cash.

AFAIK, it probably doesn't hurt much--if at all but I'd fill it up right when the light comes on for the cooling factor.

 

[Philip_G]

I would image as fuel evaporates it's quite good for cooling, I think that's a pretty common method, that one I heard form an uncle that was a mechanic for years.

 

[brentl]

"My wifes old 88 Jetta had the worst system ever; the light came on after you ran out of gas"

I guess that's the best way to find out that you are JUST out of gas, and nothing major happened.

In my Civic(2003) my low fuel light comes on with about 3U.S. gallons left in the tank.

Seems kind of dumb to rush and refill when you have another 100 miles to travel.

I also remember that Honda uses external fuel pumps, and only the pickup is in the tank.

Brent

 

[Charles J P]

My dodge truck as that DTE thing on the overhead (distance to empty). So far it has been VERY reliable, but I've never let it get below 30 miles.

 

[Carlo_M]

and #2 sucking crud off the bottom of the tank

Something my dad discovered a few years ago. He ran his tank all the way to the bottom, but did not run out of gas. However, his fuel filter got clogged and his car would drive herky-jerky as the car tried to suck gas through a clogged fuel filter.

On my 2000 Altima, the light goes on when I still have like 2+ gallons left, and I've even run it about 60 miles past that without any noticeable effects (but only once).

Usually I fill up just as the light goes on, or a little before. In So-Cal gas prices vary wildly so when I'm in an area where gas is cheaper (I like Chevron) I'll fill up if I'm below 1/2 a tank. Since I now walk to work, I don't drive very much.

 

[MarkHastings]

Their daddy sez you should never go past 1/4 tank because it will suck in dirty contaminants into your engine.

I've heard something similar too. I don't know how true it is, but I always thought that too much air in the tank (i.e. from having low fuel) isn't as good as having the tank full (i.e. less air). I wonder if it has to do with air pressure?

Hopefully someone who knows about engines can answer...There doesn't seem to be a definitive answer yet, just a bunch of people who don't trust their guages , which doesn't really answer the question if an tank with a couple of gallons can do any damage.

 

[Danny R]

Don't you know that the E on the guage stands for excitement...

I always run my 96 civic down below the empty guage and have never had a problem. I refuse to buy gas in town (10 cents higher) so I am always pushing it to get to the local station ($1.15 currently)

 

[Kyle Richardson]

Your local gas is only $1.15????????

 

[Patrick Sun]

Yup, Atlanta has some pretty cheap gas prices.

 

[MarkHastings]

I always run my 96 civic down below the empty guage and have never had a problem.

I knew someone who swore that changing his oil was unecessary. He never changed the oil and never had a problem, but does that mean it's ok?

 

[Rob Lutter]

Jez, am I the only one with a gas light that comes on about 100 miles before empty?! It's very hard to judge when to fill by the light in my car.

That said, I usually run the car till it's below the E because I live 1 block from a gas station and I know I won't have to push far

 

[brentl]

"Jez, am I the only one with a gas light that comes on about 100 miles before empty?"

Rob; not reading my posts anymore

Brent

 

[Steve_Tk]

I fill mine up when it gets to about half. Why you ask, ok. I can drive ~330 miles on a tank. The first 100 miles the needle doesn't even move 1/8th. After 300 miles it sill shows it has half a tank left. Then all a sudden you turn around and it's dropped half a tank in only 30 miles. Quality GM products! I've ran out of gas twice on this peice of crap judging by what the needle says.

I've also heard that it sucks the crud off the bottom.

 

[NicholasL]

Damn! here in LA prices just went down, but only to $1.95 for 87 unleaded. A few weeks ago, we were paying $2.20 per gallon of 87!

 

[MarkHastings]

A few weeks ago, we were paying $2.20 per gallon of 87!

I was just watching National Lampoons Vacation and the scene where Chevy parks the car (at the gas station) to buy the gun, the camera pans quickly by the gas station sign. It was too blurry to read in stop mode, but it looked like gas was between $2.40 and $2.80?? When was that movie? 1983? I assume that scene was shot in L.A. (or somewhere in Cal.) When was the gas shortage? Or has California always been that high? (Gas wise )