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Old 09 April 2022, 16:43   #1
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2 Strokes VS 4 Strokes 10HP comsuption

Hi looking for advice about What is the difference in petrol comsuption between 2 strokes and 4 strokes outboard engines in a 3 to 3.6 meters SIB with 150 kg load ( 10 HP or 15 HP ) at cruising speeds.

Any advice wellcome.
Thanks in advance.
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Old 09 April 2022, 18:09   #2
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Motors in this size use so little fuel I've never bothered to work out the difference really in regards to cost. In the 15-20hp range there is a worthwhile increase in range for the same size tank but an extra 5l spare can taken if you have a 2-stroke will offset that for the average day out.
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Old 09 April 2022, 18:11   #3
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Thanks for your answer.
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Old 09 April 2022, 18:51   #4
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Did a comparison between Two 25hp two stroke was around 15% more fuel.
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Old 09 April 2022, 19:48   #5
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That sounds about right Jeff. I seem to remember going from a 15hp 2-stroke Mercury to a 20hp 4-stroke Suzuki actually gained about 20% more range. For me, compared to the 6m+ RIB guys, it's more about getting the outboard you want not the fuel cost.
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Old 09 April 2022, 20:18   #6
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Originally Posted by Fenlander View Post
That sounds about right Jeff. I seem to remember going from a 15hp 2-stroke Mercury to a 20hp 4-stroke Suzuki actually gained about 20% more range. For me, compared to the 6m+ RIB guys, it's more about getting the outboard you want not the fuel cost.
It’s a bit loose David two stroke had a bigger boat but I had more weight, props might have been different too my guess is with two identical boats 20-25% is achievable.
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Old 10 April 2022, 08:57   #7
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Thanks for your answers.
So we could say for the same boat and same HP going from 4strokes to 2strokes ( both with carburetor )

We will need a 15% to 25% more fuel at cruising speeds?
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Old 10 April 2022, 19:51   #8
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Originally Posted by Centauro View Post
Thanks for your answers.
So we could say for the same boat and same HP going from 4strokes to 2strokes ( both with carburetor )

We will need a 15% to 25% more fuel at cruising speeds?
My engine is a fuel injected engine as apposed to a carb two stroke, sticking my neck out 15% but adding two stroke oil into the equation 20% better on cost.
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Old 10 April 2022, 19:56   #9
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Thanks again.
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