Kind of depends how you fly. Boring holes in the sky eats up fuel. In 3D work, I've found a ship with plenty of power to be fairly easy on the fuel, simply because you're not flying full bore all the time. Watch someone flying 3D with a good power to weight ratio. You'll see lots of blipping and throttle adjustment. Kind of the same principle as running higher nitro runs cooler than lower, because you can run the engine richer to develop the same power.

Having said all that, the 160 is a big motor and will go through the fuel. Sorry I don't remember exactly how much, maybe somebody else will. I haven't flown that motor in some time.