Fuel consumption of twin 350 Mercruisers

Question
QUESTION: Hoping you can give me an approximate of litres per hour- Fuel consumption of twin 350 Mercruisers in a Bertram 1989 31ft Petrol with Flybridge at 18knots per hour.


ANSWER: Hi Mark...thanks for selecting the undersigned to respond to your question.

Estimating per hour fuel consumption fluctuates based on the agee and how well the engines are tuned-up, the the overall load onboard and its distribution, including weight of all persons, fuel, equipment, aux. equipment, supplies, etc., as well as sea conditions. Obviously, you'll acquire better mileage on smooth versus heavy seas, which are influenced by wind direction and velocity. My wild guess would be an average of about 3-7L/hr.

Safe Boating
Ron

---------- FOLLOW-UP ----------

QUESTION: The boat carries 1000 ltrs of fuel and 700 ltrs of water. And majority of the time would be carrying 4-5 persons with the average gear on board.

Did you mean 37 ltrs per hour?

Answer
Hi Mark

I'm pretty confident you can do the math, so long as you know the distance from your point of departure to your destination, while averaging 18 knots/hr.

I goofed on my earlier guestimate. I meant to say 3 to 7 litres per mile, dependent upon the efficiency of the engines.

Ron