My 03 Tl-s's owner manual says my tank is 17.17 gallons, but when I fill it. It usually stops at around 14.5 gallons and when I turn on the car, the tank is passed the full. Why is that?

 

Um because the tank is not empty when you fill it up.

If you drove the car till it ran out of gas, then your fill would be pretty close to 17.17.

I don't think I've ever filled up more than 16 gallons and that was when the needle was below E.

 

+1

Gauge isn't super accurate either

 

There is a little over 3 gallons left on average when the low fuel light comes on for most.

 

that way you have about 50 miles to find a gas station after the low level warning comes on
I have put 16.8 in and that was scary enough,,,the last bit cant really be picked up and you dont want to run these cars out of fuel;- really hard on the system