When my fuel light comes on, I fill it back up and all I get in the car is about 14 gallons. I know it has a 20 gallon tank, so what gives? Anyone else have this happen?

 

Yup. It just gives you a wide margin of safety. No sense in having the light come on for the last gallon in the tank. You'll also notice the fuel economy screen showing *** on the distance to empty when the tank gets low.

CM.

 

The dealership says that the light shouldn't come on until the tank is 7/8ths empty, or about 2 1/2 gallons left. They think that it might be the sensor or a sending unit bad.

 

flyswat - Most vehicles have the fuel light come on with around two gallons left. In Nissans (at least the ones I have owned) the fuel light seems to come on with three gallons left. That is satisfactory for most folks.

Years ago, I had a 1985 Maxima in which the fuel sensor was off by about half a tank.

In most cases where the fuel measurement is incorrect, the 'fix' requires that the fuel tank be drained and the sensor (inside the tank) replaced.

If the situation with the fuel light coming on when you have three-fourths of a tank left bothers you (it would bother me), I would advise you to get it fixed under warranty now, as this type of problem seldom gets better, and often gets worse.