Gas tank issues

Hello! For some reason, my tank stops filling up at like 13 or 14 gallons. I know it’s an 18.5gal tank, and I drove it til the gas light came on one time, which I’m pretty sure means there’s 2-2.5 gallons left. However when I fill it up it stops at 14 gal maximum, sometimes only 13.5. Anyone else deal with this? I’m afraid to top it off more. Thanks!

 

Probably the fuel sender is going bad. Somewhat common issue.

You probably are simply not running the tank empty and when the light comes on, you probably have 4-5 gallons left.

Next time you get on empty, you could siphon out the remaining and see how much you roughly had left.

Before that, you can try the inclination calibration. It may have an effect: