If your concern is an EMP, then you're going to want a carburetor. Fuel gauges have been electronic for ages, I can't think of a mechanical fuel gauge system that displays on the dash.
Ironically since you mention planes, if you're concerned about that level of resilience, you want an old plane. Carburetor, magneto, steam gauges, and you can typically easily dip the tanks for fuel level. They rely on electronics for almost nothing. Also still available in operable condition.
If your concern is an EMP, then you're going to want a carburetor. Fuel gauges have been electronic for ages, I can't think of a mechanical fuel gauge system that displays on the dash.
Ironically since you mention planes, if you're concerned about that level of resilience, you want an old plane. Carburetor, magneto, steam gauges, and you can typically easily dip the tanks for fuel level. They rely on electronics for almost nothing. Also still available in operable condition.
the power and electronic-destruction potential of EMPs, even from nuclear detonations are vastly blown out of proportion. you'll be fine.