gas calculating

A thought or a ? Tundras Have a 38 gallon gas tank correct I average 13.5 miles per tank the computer said I had 125 miles to go to empty filled up stopped at 26 gallons so next time I decided to let it go farther computer said 60 miles to empty fill again while still averaging 13.5 miles per gallon still took 26 gallons this truck has never taken more than 26 gallons seems strange

 

It’s normal. I get about 13.7. Don't go by what the computer says. It's way on the conservative side. I made a video when I did a fill up at Costco.
https://youtu.be/A9VK28g3xSw

 

also be aware that when you reach 0 there is still around 10 gallons of fuel left in the tank.....Toyota does this as a feature to keep the fuel pump submerged and cool instead of running it completely dry and creating fuel pump damage. There are a few threads floating around on this.