GPH at cruise would be 55-60GPH for both engines. Don't quote me on this but cruise speed around 26 knots.
Capt J is right on. I have the CR900 and my fuel burn is 60gph at 26 knts. Thats about 1850-1900. Fuel burn really doesn't change much from 1750-2100 rpm. 4-6 gph total at most. I'm sure the 800's are close maybe a little less fuel burn not much.