TMan

Does any one have trouble with their fuel gauge being way off?

I have been complaining about mine to the dealer with no avail about how it goes 200 miles on the 1st 1/4 tank and then burns through the other 3/4 in the next 200 miles.

Also I towed my race car up to the Motorplex over the weekend and ran 315 miles on a tank when the low fuel light came on. I stopped immediately and refilled and it only took 22 gallons of my 34? gallon tank. Any fixes for this?

MikeyB

Same here. Fuel light comes on with about 10 gallons still in the tank. Don't know of any fixes.

MikeyB

Fisherguy

Just wondering if you've done the vent mod to the tank yet? If not you should.

Also I think most vehicles gauges are a little wonky, they're not really linear, you'll go a long way before the gauge starts to go down and once it does it seems to drop faster and faster.
I think (with my truck anyhow) this is because the float of the gauge does not really go right to the top of the tank when the tank is full, it's floating below the surface of the fuel and it takes a while for it to drop enough theat the float actually moves.

I've found the gauge and the DTE display to be fairly accurate though. I had the tank down recently for my AD install, it was flashing LO FUEL on the display which it does when the DTE gets down to 50km, when I took the tank out I was only able to syphon out about 3 gallons.

TMan

The tank vent was a recall item wasn't it? If so I am pretty sure I took it in for that.

Fisherguy

The recall was only for the rollover valves.

If you move the vent to the high part of the tank you get and extra few gallons into the tank and you can fill up to the neck easier without all the foaming etc.

Here's some more info
https://www.dieseltruckresource.com/...=fuel+vent+mod

Roperteacher

My 07 and my 06 5.9's BOTH would use a 1/4 tank when I got to the 150 mile mark unloaded. By 200-230 miles I was at the Half etc. never got it low enough for the low fuel light. Since I calculate mileage by hand it never really bothered me.

05HDRAM

I think they are all like that. I have the same issue - great feeling for the first 200 miles or so, then it drops much quicker. Not really a big deal, having the truck for a few years, I got used to it.

zuki_dan

I can normally get between 125-150 miles before my tank reaches the full mark. I also have the vent mod in my tank though.
My fuel light used to come on all the time a 1/8th of a tank until I ran it down so the range gauge was blinking low fuel. Now the light won't come on until it about reaches the empty mark.

Ducman82

yet again DC making a guage that does not work like it should.... joy...

2006Mega

it think it might have something to do with the shape of the tank, alittle wider at the top then slimmer towards the bottom. i need to see what shape the tank is next time i am under my truck.

Roperteacher

From what I understand the fuel in the tank cools the lift pump? Why would anyone want to run it low unless they had too.

hivoltage

Yeah kinda like their fake oil pressure gauges.

DiezelSmoke

Teacher, has the correct answer, it is designed to keep the pump in the fuel tank cool. All cars and trucks have the same fudge factor for this reason.

rvman

Give me a break ! Every Chevy I drive at work does the same thing.

Pirate

I heard a story one time, not sure if it is true. Most manfacturers have the fuel gauge set up to do just what most are saying. It stays on or above the full mark for a long time then drops quickly. This gives a "perceived indication of better fuel mileage". The story goes on to claim GM correctly calibrated the fuel gauge on a certain model year Caddy but went back to the original calibration after receiving numerous complaints of poor fuel mileage.

My '07.5 has a fuel gauge more correctly calibrated and I have to admit it seems to go a lot faster to empty because it does not stay on full very long. Yeah, I know I am getting much poorer fuel mileage than my '99 and I hand calculate on occassion but the over all perception is worse than it really is.