APU fuel usage

[UniFoxOs]

Probably a silly question but after sitting for a few hours in a 767 recently waiting to be able to take off (snow) with all the lights, cabin air etc. running, I wondered how much fuel does the APU use? Would it ever use enough to necessitate topping up the tanks again before take-off?

UFO

[strake]

http://www.pprune.org/tech-log/356069-apu-fuel-consumption.html

That jolly old search key comes up trumps again....:ok: