16 USG per hour for the recip. engine O580. as trip fuel
Declines marginally with full carb heat on full all the time.
Watch out for :-
a. Ground burn time (taxi fuel usage) to account for part of the full fuel load
b. Asking for full tanks and the fueler not topping off to full both sides. Reduces fuel load by about 4USG and reduces available trip fuel plus contingency amount. Can be an issue if near range limitation.