Yeah... I got about 6 minutes at WOT initially but I had my engine seriously out of tune at the time.

It was spitting out much more fuel than it was consuming...

Once the engine was broken in I've been getting about 15-17 minutes to tank empty at WOT ( I upgraded it slightly to a full dubro 12oz tank I really need a 14oz tank in it though.. ).

I have my timer now set to 14 minutes for safety as you DO tend to fly this plane as fast as you can...

5 minutes is far too much consumption for the O.S. .55.

It should eat up no more than .7oz/minute at Wide Open Throttle.