Outboard Fuel Consumption

[sal garfi]

Hello All,

For those who have 4 stroke outboard motors on their boats, can any of you give me an idea of your petrol consumption? I have a 15hp Mariner 4 stroke and I will be taking a long journey through the system this coming September (that is, if all goes according to plan!).

Any info would be really helpful. Thanks!

Sal

[PaulG]

The old "rule of thumb" for 2-stroke outboards was a pint per horsepower per hour.

Does depend on whether you are pottering or hooning around, and also the type of hull it is driving. Maybe 4-stroke outboards are a bit more efficient these days as well.

I've also heard of a litre per 10 HP per hour being used as another way of estimating consumption.

 

[sal garfi]

Ooohh..., I'll only be going the speed limit, so around 3-4 miles an hour, and the boat's a Norman 22.

[Mike Hurley]

At canal speed it should be about 2 litres an hour at the most if engine is in good condition. My 9.9 2 stroke uses 4 litres an hour at max speed.

[sal garfi]

Well, the motor has recently been serviced, so 30 litres should do 15 hours?

 

[Mike Hurley]

Should do but remember to count time in locks etc. Engine running time is not the same as cruising time.

[sandgrown]

We have a 9.9 Honda on our Caraboat, and we do about 1.5 litres an hour. with no locks we cover about 3 miles an hour. The engine is an older one so a new model may be a bit more economical, heavy weed and shallow water can slow you down a bit too.

[sal garfi]

13 hours ago, Mike Hurley said:

Should do but remember to count time in locks etc. Engine running time is not the same as cruising time.

I appreciate that, and if, like sandgrown, I'd like to think that 1.5 litres per hour would be my average.

[jocave]

My 9.9 with a 13 ltr tank just about manages 10 hours of running before a refill, depends on if we are going with or against the flow but on average I would think a good 9hrs for 13ltr before we need to think about a refill

[max campbell]

I measured our 4HP 2-stroke Mariner at 30 mpg pushing a 650Kg sailing boat hull at canal speeds, over about a week's cruising.

[sal garfi]

11 hours ago, jocave said:

My 9.9 with a 13 ltr tank just about manages 10 hours of running before a refill, depends on if we are going with or against the flow but on average I would think a good 9hrs for 13ltr before we need to think about a refill

So this works aout at ca 1.4 ltr per hour. I think there's a trend here?