Driving & Driving Test Tips: gas mileage, best gas mileage, empty tank

Question
i was wondering if its true that for best gas mileage you really should keep your cars tank as full as possible. thanks. (im sure with the high prices today you can see why im curious...)

Answer
It makes absolutely NO difference if you have the tank full or near empty, other than if you constantly run it empty, you will have to stop more often and THAT will reduce your mileage.  Otherwise, it has no effect.

the only other effect of running a nearly empty tank is that if there IS any junk in your gas tank, it is more likely to be sucked into the filter in the tank and stop flow, but that doesn't happen much.

The best reason to run a gas tank full is so that it doesn't get as much condensation (water) in the tank.   Also, you run out of gas less often and don't have to push the car!  :)

For cars that sit a lot (collector cars etc) a full tank helps prevent rust and condensation while they are stored.