outboard fuel consumption.

[Chadgro]

Has anyone ever compared consumption of (to simplify things) a 5 hp outboard at full throttle to a 10 hp at 1/2 throttle?
I am choosing an engine for a sailboat and would like plenty of power but am also concerned with range/fuel consumption.

 

[kenmyfam]

Re: outboard fuel consumption.

Never tried it but I would imagine that it would be pretty even with less wear on the bigger motor.
Most important thing is to have the correct size motor for your application.

 

[kbait]

Re: outboard fuel consumption.

If you were talking about a small boat that would plane out w/a 5hp, you'd get way better mileage from a 10 hp at 1/2 throttle. But since you're just pushing water, my bet would be on the 5hp using less fuel. Consider a power, or 'high thrust' prop to get your motor closer to optimal rpms as 'lugging along' isn't efficient at all, with either motor choice.

 

[bktheking]

Re: outboard fuel consumption.

You'd want an extra long shaft for a sail boat, probably easier to obtain a 9.9 Sail than a 5 hp extra long shaft, pretty rare I'd imagine.

 

[steelespike]

Re: outboard fuel consumption.

Rule of thumb a motor will use 10% of its hp in gph(gallons per hour) at wot(wide open throttle) Whether pushing a house boat or a dingy.9.9 Would be a little less than 1 gph.Obviously you could throttle back to save fuel.Pushing your sail boat at speeds within displacement speeds about 6mph will save fuel.

 

[Solittle]

Re: outboard fuel consumption.

In my view fuel consumption on those size motors would be the last thing to consider in a get home motor. You don't tell us the size of your boat but 9.9 longshafts are the most common here in Florida in the 21-26' class.

 

[Chadgro]

Re: outboard fuel consumption.

Thanks all for the input.