I know this question is very similar, but I am specifically talking about the fuel gauge and not an indicator light. Almost every car I've owned could run for quite a while with the fuel gauge reading an empty tank.

Is there some standard (either enforced or just customary) in the US for calibrating fuel gauges as to how much wiggle room you have after it technically says you are out of gas?

I know my own car's limits fairly well (at least as far as I have tested them), but I'm curious in the context of an unfamiliar car, for example a rental.

1 Answer 1


There's no standard. It depends on the fuel gauge sensor, the feed location in the fuel tank, the length and size of the fuel line, and the size of other items in the fuel line such as inline fuel filter and carburetor/injector setup.

  • 1
    Although it varies by car due to the tank size and such, I have seen that usually the manufacturers have the warning come on when you have a quarter of a tank left, or a couple of gallons (I forget the exact amount) although usually fuel gauges aren't 100% accurate as gas sloshing around can affect the sensors causing slight deviations.
    – theonlylos
    Sep 12, 2011 at 18:59
  • In our 96 Explorer, 01 Prism, 03 Caravan and 97 Caravan, the fuel gauge light comes on the bar right above the E (which should be an 1/8th of a tank or ~2 gallons which should get you roughly 30-60 miles) Our 01 Focus has a weird gauge though its only marked in 1/4ths not 1/8ths. Not sure when the light comes on.
    – Robbie
    Sep 21, 2011 at 16:40

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