Shrinking Fuel Tank!

[MadDuraMax]

OK, got your attention. Just how accurate are your fuel gauges?

My last 3 fills:
1. Just over 1/4 full reading - 27.8 Gallons to Fill
2. Just under 1/4 full - 24.8 Gallons to Fill
3. 1/8 tank reading - 26.0 Gallons to Fill

I've got the long bed, 34 gallon tank. Maybe the darn tank is shrinking :( , then maybe I'll be one of those old guys who throws rocks at pigeons :D

[sw11497]

Not sure how you usually fill your tank but, I have also noticed this. It has to do mostly with ambient temperature at the time of the fill from what I was told. Diesel expands more dramatically than gasoline. I always try to run the fuel up the neck until the foam has completely cleared away and all I can see is liquid. This is very important if you are trying to get a good mileage reading but, don't do this in hot weather and then park the truck. The diesel will expand and possibly leak from around the filler neck. This is one reason semi tanks don't have the filling cap directly on top.

[needbigtruck]

I don't think your tank is shrinking. I also have the 34 gallon tank and have noticed that from full (fuel visible in the filler neck) it's about 6 gallons to reach the full mark. Then it's about 2 gallons per tick mark until you get to 1/2 full. After that it goes down quick. It appears (I haven't verified by filling) that it goes to about 1 gallon per tick below 1/2. I've gone to low fuel light twice and it's always come on with 3 gallons left (verified by putting 31 gallons in tank) and it comes on just above the "E". So bottom line is the gage is not linear throughout it's range, it goes down quick below 1/2, and when that low fuel light comes on you better get fuel.

[MadDuraMax]

Thanks for the input guys.

I fuel my truck as follows; fuel until the autostop comes on, wait 30 seconds or so add about 1/2 a gallon, wait..bounce the truck a little keep adding. The top off process takes about two minutes and adds about a gallon to the tank, I don't always wait to see fuel in the filler neck though.

I've noticed that the gauge reads non-linear (200 miles for the 1st 1/4) but I was surprized to see it reading @ 1/8 full and having 8 +/- gallons left on the last fill. This seems to be getting worse with each fill up. Glad to hear your low fuel light seems pretty accurate, there is some comfort in that.

I'm planning on keeping a closer eye on it the next few fill ups, I'm still trying different stations for fueling to see which one works best.

BTW Diesel is up to $1.499 here $.10 higher than 87 octane unleaded. :(

[Mark Heiken]

Same thing with mine. It's not consitant at all on readings below half. Low fuel light on once- only held 27 on 34 gal. tank.