Chevy & GMC Vans

Hi guys, new member here. I have a '99 conversion, and I am surprised at how much I enjoy driving the thing.
Looking through the Haynes manual, I see that the tank capacity for '98 through '00 is 25 gallons, and the capacity for several years before and after those years is 27 gallons. Does anyone know why?

JayDubya wrote:Hi guys, new member here. I have a '99 conversion, and I am surprised at how much I enjoy driving the thing.
Looking through the Haynes manual, I see that the tank capacity for '98 through '00 is 25 gallons, and the capacity for several years before and after those years is 27 gallons. Does anyone know why?

I really don't have an answer. But, I have a thought. My 05 is spec'd with a 27 gallon tank. I've never been able to put more than 22 gallons in it. Gauge reflects empty at that point. That being said, I don't think it's a good idea to run all of the gas out, Because the touchy and difficult to replace fuel pumps use the fuel in the tank for cooling. Jim

Welcome to the site, Jay. My 96 SLX Safari is rated at 27 but the most I'v been able to put in it is 24. And that is when I ran out of gas and and was lucky enough to coast into a gas station. I think the engineers use a mathematical formula to determine capacity instead of actually measuring.

Smiles,
you couldn't be more correct! One of the biggest discussions we ever got into when we worked at GM was how the devil do you figure out the capacity of a tank! Gas is a relative volume, its density changes with the temperature, humidity, etc. I suspect that 5 different vans with the same tank would actually end up with 5 different capacities! This is the reason why the standard disclaimer in the owner's manual about ..."actual results may vary". It also reminds me of the comment cards we used to get at Wentzville when we began to offer the outside temperature display on the ATC HVAC units. The Plant manager and I used to laugh at the comments of "my thermometer says that it is 85 degrees outside and the thermometer on the bank sign that I just drove by said 84"! The reason that the capacity was increased was that the customer base uttered enough complaints that the engineers listened. That, and the dies for the tank needed to be replaced anyhoo...

Interesting. So we are not even sure if there was actually any difference between the 25 & the 27 gallon tanks, eh? Who'da thunk it?
I was hoping that someone could tell me if the earlier or later (27 gal) tank would fit my '99.

My tank is rated at 27 gallons and I actually put 25.5 in it once, but the needle had been pointing to empty on the gauge for quite a while. It probably indicates empty a bit before the tank actually is empty.

as the summer gas prices peak, it will be holding a capacity known as "freaking expensive"

IF ive run out of gas 10 times in my 62 years, 7 have been in my 1999 ASTO. The Gauge LIES. The Miles left in the tank meter LIES.. Mine will hold 24 gallons ABSOULUTELY OUT OF GAS.

I use the Odometer to keep up with when I should refill. if its past 300 miles I fill up. BUT, if im towing something like my boat or my larger landscape trailer, I need to find gas sooner.

That being said, I like the vehicle............. I JUST WISH i could trust the gauges. ANY EASY SOLUTIONS for making the gauges a bit more ACCURATE??????????????

earl

I usually fill when the gauge says between 1/8 and 1/4. After a few tanks to get calibrated, my ScanGauge is pretty accurate. Green I can go about 520 miles and put shy of 24 gallons in. Grumpy is on it's first full tank in a while, looks to be good for 480 miles though.