Fuel usage

[Donna]

Does anyone have an idea on what the fuel burn would be on a 55ft. 17.6ft. Semi planning hull design with 2, 728hp. Detroit diesels?

 

[GoneDiving]

Fuel use grows exponentially with speed so what speeds are you asking about?

I've found power and fuel calculators remarkably accurate for my vessel.

https://vicprop.com/planing_size_new.php/?m=1

Divide by 4.7 to get litres per hour or 17.8 to get US gal/hr. But the short answer is "a lot". 1450hp is 80 gal/hr at full noise.

 

[Donna]

I was thinking around 10-11 knots. Just want the speed on a Following sea.

 

[GoneDiving]

My 50t 54 footer uses 18ltrs per hour at 8kn. I'd use double that at 10kn.

 

[Donna]

My 50t 54 footer uses 18ltrs per hour at 8kn. I'd use double that at 10kn.

Thank you for the calculation link. I don’t mind doing 8 knots as that is what my current boat likes. My new one is certainly going to use much more fuel, but the speed is there if and when I need it. I can live with 18-20 ltrs an hour