I think what he was wondering was... if you go get gas when the needle reads a quarter tank and the light comes on, do you get like 17 gallons in, or like 12?

The gas tank has two seperate sensors in it, one to control the gas gauge, and a seperate one to control the "low fuel light". They're different style sensors as well, and the low fuel light seems to be the more accurate of the two.

If you can get 17 gallons in it when the light comes on and the needle reads a quarter, that would point to problems with the gauge, if you can only get like 12 in, that would point to a problem with the low fuel light sensor.

Or maybe I'm just totally confused...