v8v fuel gauge

[john ryan]

Full tank at the bottom of the Grossglockner, and the gauge was reading empty at the summit; on the way down, the reading came back up. Obviously atmospheric pressure having an effect, but can anyone explain? I vented the tank to equalise pressure on the way down, and the gauge instantly corrected, No ill effects on performance on what is a glorious drive going north.

[TuonoPants]

Did you brim the tank? This can cause an air-lock and the gauge will read zero until it clears either by the level dropping or movement of the car. I've seen this a couple of times and the advice is not to brim the tank to prevent it from happening.

[john ryan]

Noted and thanks. This one was definitely variable with altitude, but since we are now on the relative flat I doubt it will repeat.