Fuel consumption 4207 with Mercruiser 350s

[bobwhorn]

Is there a chart of fuel consumption at different sppeeds/RPMs? Coming from a sailing background where that was never an issue.
Thanks,
Bob

[waybomb]

Simple rule of thumb. One half pound of fuel for each horsepower per hour.
Gas weighs 6 pounds per gallon.
So let's say you are using 300 hp between the two. That's about 25 gallons an hour.
If you are wide open, 700 hp, 60 gallons an hour.
It's expensive to run this boat with gas engines.

[g36]

This website is a good place to check for estimated use...https://www.boat-fuel-economy.com/outbo ... us-gallons

[bobwhorn]

Messed up, the engines are blue so I am told they are Crusader 454s.

[g36]

Same website just select crusader and the engine displacement and see estimated fuel flow at various rpms.....https://www.boat-fuel-economy.com/crusa ... us-gallons

[bobwhorn]

Thanks, missed the part about selecting engine type and size.

[MyPleasure]

Hi bobwhorm, I’m not sure that that website uses the Crusader carbureted 7.4 or just the MPI engine’s specifications. You might find that the carbureted 7.4’s will use a bit more fuel than the fuel injected 7.4’s. Our 1992 Carver 36ft aft cabin with carbureted Volvo 7.4 engines use about 5gph each (according to the fuel floscans) at 1500rpm, giving us a cruising speed of about 8.5 knots.
Just to give you a real time example of fuel use.

[MyPleasure]

And by the way, the 4207 is a much larger boat than our 36 in every way, so your fuel consumption would probably be even more than our 5 gph at the same 8.5 knots!