How accurate are the gallons in fuel tanks ?

The gauge is weighted so you don't run out of fuel.
Not real smart to run your tanks low..but just keep running them to empty and let us know..

 

The gallons marked on the tanks are 95% of the actual tank capacity. I have 2 100 gallon tanks on my pete and have ran it down to where Ive put 195 gallons in but I also fill my tanks to where its just about to run out of the filler hole. Depending on the fuel blend, pump rate, and style of nozzle I can normally get 5-10 gallons more into the tank after the nozzle clicks off.

I’d say your running them to about as empty as I’d wanna run them on a normal basis.

 

The tanks are turned alittle, and u can't fill to top, yes maybe 10 gallons short on each so figure 40 gal times fuel mileage,,,,, figure 5

 

With two 70 gallon tanks, I pushed ~100 miles past the light coming on, and topping off only put in like 115 gallons or something. The next time I tried it I wasn't as lucky. I don't push it below 1/4 tank anymore.

 

So the light comes on, how many gal r still n tank.......... The manufacturer sets it at a certain , same n your car,...... DON'T!!!!!! DON'T!!!!! EVER go by your Gage, use a stick of some kind or just fill up at a certain mileage

 

odometer is best way to go, if you are really curious carry some extra diesel somehow and run it dry, then you'll know exactly what you can get away with

 

If that's your milage, I'd think About a different truck, or learn momentum

 

I wouldn't want to run it that low but get yourself a stick and measure the tanks when that light comes on to know how much is left at that point.

Those are small tanks and your fuel mileage seems pretty bad. Just curious, what are you driving?