I need somebody to fill me in on this mystery. From my understanding my short box has a 26 gallon capacity tank. I have never put over 24 gallons in at one time. Last Sunday I was on my way home from Indy and I couldn't find a fuel pump for the life of me. I started to get really nervous because my indicator was below the orange line. Finally, I pulled off at a truck stop and filled up with the big nozzle pump. I filled the tank to the brim.......... accidentally, and the pump read 26.9 gallons. Does this truck have a 2 gallon reserve in addition to the 26 gallon tank? How is this possible? Anyone else had the same experience? Thanks

ive never been that low

odd. perhaps the pump wasn't calibrated correctly?

oh, do you have the larger filler neck? I'm making a long trip this weekend and wonder if I'll be able to fill @ truck stops.

I have the long-bed with the larger 34-gallon tank. I have never filled it with more than ~31.5 gallons, so your experience parallels mine.

I'd say the pump was off and you paid 10% more than you should have for the actual amount of fuel purchased.

A 76 pump once said I put 28.8 gallons into a 26 gallon tank. Don't know how or why, but I'm assuming the pump was off.


Andy

I have put 26.5 gal in a couple of times.. but i know it was bone dry.

yes if you run it to orange line on the fuel gauge it is possible to put over 26 gallons in the tank, but you have to pump until it even fills the neck. filling to the neck or threads is the accurate way to check fuel mileage

I'd say the pump was off and you paid 10% more than you should have for the actual amount of fuel purchased.
I agree, If you were able to put that much fuel in I would say that the pump isn't calibrated. Some station operators are toying with their pumps to do this. I would report it myself.

weird

I've been to "tight sphincter country" with my OEM and put 26.4 into it when I finally got to a station. But that was an unusual circumstance, and I've had my 40 gallon aux tank on board since Dec. of 2001.

That happened to me once also. I assumed that I got screwed. IMO, if it is running it should not hold over 26 gallons in a 26 gallon tank. If it is actually out of fuel then maybe a tad over. I think the mfr knows exactly how much fuel these plastic tanks hold.

Could also possibly be that the pumps have for a while now take in to consideration temp of fuel and volume compensation.Says on the pump "corrected to 15 Deg well here in Canada anyways. Depends on ground temp, fuel temp, tank temp and such.So it is possible to put more than it will actually hold if the temps are rite.i will admit that some pumps just aren`t calibrated correctly either tho.Being a service station tech i run into that from time to time.usually the call to go there to calibrate.

I've put as much as 36.7 gallons in my long bed 34 gallon tank. Of course that was after filling to the brim and pushing the truck up to the pump.:banghead:

I really appreciate all the feedback guys. I guess that I should just make sure that I fuel up earlier next time so that I don't have any reason to post on this subject......LOL.

The fuel tank capacities aren't that accurate.

By filling all the way to the top of the neck you are adding capacity to your tank. GM rates the tank itself not the tank and the fill pipe. I always fill my tank until I can see the fuel just below the top of the tank. It takes a little longer to do because of the foam but I always know the tank was filled the same for checking mileage reasons and I can go a little longer before filling again.
Mike

X-2:driver:

x3

The GM policy is to round the volume down to the next lower gallon. This makes good sense in terms of being conservative and not running out of gas.

So, a 26 gallon advertised tank may hold 26.9 all the time. There is also regular variation in the tank manufacturing. In a large truck tank that could be +/- several tenths of a gallon.

I wondered about this also. I went to a shop that repaired them and was told the reason you can sometimes put more in than GM states is that the neck actually goes down into the tank slightly, leaving a small air pocket at the top of the tank for expansion of the fuel. So if you pump and go slow at the end, you will start to fill that void space.

I have the 26gal tank in my ’01 short bed gasser, and I have put as much as 28gal in it, (not overflowing out the fill neck), and I have done it many times, and at a various number of stations, so I tend to believe that GM guesstimates it at 26gal, because they know that it will hold at least that much. I don’t think that many stations are off by the same amount. Also, another tidbit on that, I never had to push it to the pump, so it must hold a bit more than that.

Normally I top off at 3/4 no less then 1/2 and for the most part I can guess how much fuel it will take to fill it and I get pretty close. I went as low as 1/4 today and fiqured on about 24 or 25 gals. It only took 19 gals, shocked me.

I've put 35.66 in my LB but i do top it off every time.


I once put 37. 5 in my old 97 6.5

I've cut it close a couple times, but once while on 94 going across North Dakota at like 2 in the morning the needle was below empty, low fuel light was on, and there wasn't a station in sight. Thankfully found a station in some little dump of a town and the pump said i put 29.60 in my 26 gallon tank.

I've put over 26 in my truck many times according to the pumps at least...