My truck came from the factory with the 36 gallon tank.
When my fuel gauge says it's empty and the computer says 0 miles to empty, the most I have ever been able to put in the truck is 29 gallons.
I wonder if my computer was programmed to think I have the smaller fuel tank? Or does anyone else have this issue?

 

I put 32 gallons in mine once, never got more in it.

 

I've got the 36 and when it reads empty on the needle/hash mark it will take on about 32.5-33 gallons. I have only run it lower than that twice, then 35 plus gallons.

 

I would say you have something not right, it may be programmed for the wrong size tank. I have no problem getting 32+ in mine and usually fill up with ~50 mi to go.

 

You could try this as a one time deal - fill up a gas can and throw it in the back of the truck. Run it out of gas, dump the can into the tank, then go fill up. That should tell you if you really do have a 36 gallon tank.

This really is only feasible if you are driving around town or somewhere where there are plenty of gas stations. You also don't want to make a habit of running the tank low, the pump relies on being immersed in fuel to keep it cool.

 

The original truck invoice and window sticker say 36 gallon tank.

I'm going to see how many miles I can go past the 0 miles to empty readout. I'm going to pull a Kramer from Seinfeld.

If I can go another 70-100 miles, then I know it's programmed incorrectly, I guess.

Say that I determine this...I didn't reprogram the computer, the dealer must have. How do I convince them to fix it for free?

Not sure how the computer knows when there's 0 miles left. If the gauge shows empty and there really is 6 + gallons in the tank, why would the gauge read empty? Does the miles to go computation come from the level of fuel in the tank or from estimated consumption?

 

This would be a non issue for me. I usually fill whenever convenient after I go below 100 miles to empty. Normally around 50 miles to E. I can pump 30 to 31 galons at that point. Like mentioned above, your fuel pump relies on being immersed in gas to keep it cool. You are not that far from normal operation.

 

Mine is at 0 with 30.5, so you are not far off.