pwirch

It says that my truck has a 34 gallon tank but with it at about 1/8th tank I fill up 24-25 gallons and it's full. Is there really almost 10 gallons left when I'm at 1/8th tank? I've only filled it up three times so far, the gas gauge light has never come on but the needle gets to between 1/8 and E. I'm always right around 24-25. Not that it really matters because I'm adding a 90 gallon auxilary but I was really curious about this since I've got my Glacier fuel system on the way and was wondering if there was something not right with my tank.

bdewey

Mine does the same thing not sure myself. Would like to know what people have to say.

Sailpipes

The tank is made with about 8% of the capacity as reserve. When I did the tank vent mod to mine which requires dropping the tank, I ran it several miles past DTE reading 0. There was still at least 2 inches of fuel left in the tank so it sounds to me like everything on yours is working as intended. My low fuel light usually comes on right at 1/8th tank though.

bumpytruck

Do a search on "tank vent" If you do this mod you can get an additional 4-5gals of fuel in your 34 Gal tank. I think this throws off your DTE as it is programed for 34 gals.

pwirch

I ordered a tank vent kit today with my glacier fuel system so it's nice to know that will fix this issue. My DTE will never be right anyway because I've got a 90 gallon in bed tank that I'm putting in and hooking it to my factory tank. Once I know the 90 is empty I'll be planning a trip to the res to get fuel.

moterhead

No, there's not 10 gallons left. It's more like 14 to 15. I put Dave Kelley's tank vent kit on my '04. I was one of Dave's first customers. I have gone as far as 825 miles on one fillup. Gone 100 miles with the low fuel light on and 50 miles after DTE reads 0. No, it never goes into negative numbers. The actual capacity of the "34" gallon tank is right at 39 gallons. Also, talking about DTE. The DTE computer function will only calculate based on a bit over 30 gallons. I take my DTE when full and divide it by MPG. Almost allways comes out to 30.1. With the vent kit, DTE will often not change until there is over 100 miles on the tank.

12PACK

Are you letting the foam settle? And what's this about a gas guage?

pwirch

There must be something wrong with my truck .. I get about 320 on a tank (well, 24 gallons). That's in the city though, stop and go all week. I'm going to take it in and have the computer checked, make sure I have the right stock program in it. It seemed sluggish for an HO from the day I got it and my 99 got 18-20 around town with a torque dog. Being easy with the TST I'm now seeing about 15mpg. Still not very good. If I hit the highway I get around 21mpg average according to the overhead if I reset it while I'm cruising at 70mph.

steelblitzkrieg

I fill it until the fuel is an inch below the vent hole in the neck.

I filled up on Feb 5th, I commute 23 miles each way at an average of 30mph between stop and go and true highway speed. I use my truck on the weekend for errands and what not. I have driven 407 miles and have 177 left according to my DTE. Before I started topping it off it would say on a full tank 440 DTE.

If I take my 407 + 177 = 584 and then 584divided by 38gal (worst case) I get 15.36mpg, which is wrong because I averaged 15.9 last tank before starting to use PSP, which claims 8% increase (1.2mpg) so it would be 17.1mpg, even if I half it at 4% I would still be getting 16.5mpg.

16.5MPG X 38Gal. (worst case) = 627 miles

The first time I did the top off I also took the 440DTE and divided it by the 14.4mpg that my O/H was telling me which gave me 30.5 gallons as someone said earlier.

I was able to put in 34.17 gallons when my DTE claimed I had 44 miles (IIRC?) Using the DTE and O/H as a guide that would be 3.05 gallons in the tank at the time of adding the 34.17 giving me 37.22 gallons total. Being that the DTE reads at 30.5 gallons I figured that I had 3.5 gallons on top of the 3.05 that it was claiming, but that would give me 40.72 gallons squeezed in?

Using hand calcs at 15.9 when it read 44DTE I had 2.76 gallons left before adding my 3.5 and my 34.17 I get 40.43 to top off?

I know the 44DTE is wrong because I was getting 15.9mpg not 14.4 so it should be a lower amount of gallons left, but all I can come up with is the low fuel light comes on at 8% left in tank 2.72gal left per capacity and 2.44gal if I use the 30.5 guide?

So my best guess is 40 gallons.

Someone shoot me if I'm wrong please.

SSminnow

I guess I will be the one that has to say your math is off, or your odometer one. 825 miles on a tank of fuel????? Come on. I get 500-550 miles driving 65-69 MPH. To get 825 miles on a tank you have to be driving like 30 MPH. I am a non believer on this one, sorry

steelblitzkrieg

I think 825 is doable if you top off and get a consistent 21mpg, but a lot would have to work in your favor.

My commute is 23 miles one way and it takes me 45-60 minutes.

I get 15.9 commuting (Before PSP) and if I just had 34 gallons it would be 540 miles.

15.9 X 40 = 636

I think your DRW hurts you a bit other than that, I don't know.

rodsram

I have done 735 mls on a tank quite often - Myrtle Beach to Louisville KY.

I drive a constant 5mph above the posted speed limit.

I have a GPS that reads at 65 / 70 / 75mph is 2mph slower than my speedometer.? - relatively the same at 50 / 55 mph.

When ever I fill-up, the DTE will never go higher than 620 mls. - Any one else have this happen?

pwirch

I'll check what my DTE goes to when I fill up today. I've got 1/4 tank left right now and between my last tank and 3/4 of this one I've done just over 500 miles. All city but still, that sucks.

500 miles, 24 gallons first tank, 18 gallons so far this tank (estimate).

That puts me around 11.9mpg around town. Now I know I've been a heavy foot this past week since I got the TST in but that really sucks.

J Banning

Before I did the vent mod, I ran the truck down to "0" DTE. I still had 7 gallons left in the tank. When I filled it up, it took 32 gallons more(!!).

After the mod, I can still run the truck to "0" DTE with no problems.

The vent mod is well worth it! It's soooo easy to top off the tank now. The pump doesn't trigger till about the last 1/2 gallon is left.

danc46

The tank reading is purposefully off from the factory. Because diesel may be hard to find in certain areas, the factory built in an 8 gal reserve when the tank reads empty. I know my 2000 was like that as is my 2006. If the low fuel light comes on, I will still only use 24 to 26 to fill my tank.