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How far can you go after your fuel light comes on

33K views 23 replies 16 participants last post by  navybob 
#1 ·
The answer for me today was ~60 miles, about 1/2 of it in stop & go traffic. It started to stumble on hard acceleration (is there another kind of acceleration?) so I decided it was time to get gas. :)

Incidently, I got 330 miles out of the tank, including racing it and towing with it this weekend so thats not bad.
 
#3 ·
Light comes on around 11.5 gallons gone (~3 gal left). Average mph is about 20-25. So 60 is about right.
 
#4 ·
If I were Moderator for a day..........

I'd move this topic to the right place :)

Other than that, I'm glad someone out there was brave enough to drive around and wait until his car ran out of gas, so I wouldn't have to do it. *makes a note*. I will now set trip meter B to 0 when my light comes on and fill up at 59.9 miles. :wink:
 
#8 ·
The theory is that you have little bits of sediment or debris in every fuel tank and that builds up in your gas tank. People say when you run your tank really low the sediment is super concentrated and can clog your filter or get into your engine.

Maybe that's valid if you NEVER let your gas tank get low and for some reason are forced to (can't find a gas station or something) but my opinion is that if you regularly run your tank low it won't have the chance to build up.
 
#9 ·
Ive only been able to juice about 40 miles after the light comes on. Then again, I havent ran it till the motor studdered.. came to the conclusion I didnt want to run out so I filled up.
 
#12 ·
Other than the possibility of stumble if you fuel pump intakes some air, generally under hard acceleration or cornering, it's unlikely that there would be any power loss with a low tank of gas.
 
#14 ·
k.. so my light came on and i went to get a fillup right away. fillup was 10.759 gallons, and the tank capacity is 14.5 gallons, so that is 3.741 gallons left. I calculated my mpg (314 miles) for my first tank after the dealer fillup at 29.185 mpg.. so, at that rate, i would get 109.181 miles before i went empty.


You don't want to run your tank to near empty. I usually don't let it get down below 1/4. starts to suck sediment from the tank if you go all the way down.
 
#15 ·
I only got about 12 gallons in when I filled up, and that was after letting it start to stumble. I'm pretty sure youd run out of gas long before you got to 14.5Gals.
 
#17 ·
Yeah the crap in the tank thing is true, but running to an empty tank mainly dangerous because then its all fumes in the tank, and causes them to become under greater pressure, so we all learned in physics, fumes has more surface area than liquid, so its more ignitable. It's a low risk of course, but even a small spark at the gas station could screw you over in that case.
 
#21 ·
icecube said:
do u guys feel that the car got less power when is low on gas? or is it just me
Have you had any issues with the fuel pump? I would say that since the fuel pump issue is a lack of line pressure, that would make sense to me. Less gas in the tank, then less likely it'll force it to the engine.
 
#22 ·
DJ Spencer said:
icecube said:
do u guys feel that the car got less power when is low on gas? or is it just me
Have you had any issues with the fuel pump? I would say that since the fuel pump issue is a lack of line pressure, that would make sense to me. Less gas in the tank, then less likely it'll force it to the engine.
A pump is a pump. As long as the feed into the pump is completely submerged (or the pump itself, depending on the design), it doesn't care how much fluid is in there. It either pumps air or fluid. A fuel pump (or any pump) will flow at the same rate regardless of if it's just barely submerged or if it's at the bottom of the ocean. If it doesn't, there's something wrong with it. The source volume has no effect on the flow capacity of the pump.

Perhaps what icecube feels is the weight difference. Though it's less when the tank is low, which should mean better performance, it's possible that the butt dyno doesn't perceive it this way. From a technical/physics standpoint, there's no viable reason that the car would perform worse with less gas in the tank than with a full tank, unless it's so low that it's ingesting air.
 
#23 ·
I think that was what I was getting at, but now I don't remember.

I'm now running 22mpg on my second tank after the new fuel pump. That's a gain or 2 mpg. :)
 
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