Edited - Sorry, I was being repetitive. 1/2 flaps for takeoff are fine for me, but a little up elevator was required for 1/2 flaps slightly more with full flaps and gear down.

On my P-80, it uses 8oz/minute and I have a UAT, center hopper tank, and 2 saddle tanks. This gives me between 6-8 minutes depending on how I use the throttle. This also allows for a few fly-by's incase I don't like the approach.

Hope this helps!</p>