The blue one as my avatar had a Deutz 1013, 261hp @ 2600 with a 4 to 1 twin disc 507 turning a 38x33 four bladed wheel and cruised at 7kts @ 1900 using two gallons an hour.
It's a Lister Petter LPWS2 with a PRM 150 hydraulic gear 3 to 1. I'm setting it up for 18hp @ 2600rpm turning an 18x15 three bladed wheel, my goal is to use one quart per hour at 5kts and maybe do the loop.