gasmileage

[bigCountry]

Is it normal for a firebird to burn threw a half a tank quick, it seem when my car has a full tank its gets really good gas mileage but from a half a tank i could be drive a short ways and watch the need move slowly down

[camaro_guy]

Mine does that, it takes forever to get to half tank but after that it just drops.

[HokieBird]

Our tanks are shaped like a V so our gauges aren't really accurate. It is completely normal to go "threw" the second half (according to the gauge) quicker.

[rhouse21]

As HokieBird said, our tanks are roughly triangular in profile, so they little float in there doesn't do a great job of telling you exactly how much fuel is left in there.

Based on 8 years of driving observations, on my car:
Full line = ~3/4 tank
3/4 line = ~1/2 tank
1/2 line = ~1/3 tank
1/4 line = ~3-4 gallons (depending on time of day and/or phase of the moon)
just over empty line = ~2 gallons

...but I'm not sure that this is the same for other cars.