Outboard Fuel Consumption

[MMNETSEA]

In the Topic "Liferaft Madness?" in the Cruising and Sailing Forum(Current Topics) the use of a dinghy was discussed.

I read somewhere of an easy method of determining the average fuel consumption of an outboard on a RIB at full throttle :- "The standard consumption of almost any outboard engine is 10% of it's horsepower. Example : a 15 HP 2 stroke engine will consume 1.5 gallons an hour. "

One good test is to put one gallon, maintain a specific acceleration with out any throttle variation and see how much time you run till the engine stops.

Run at cruising speed and see how far you can cruise with one gallon.

Also to be taken into consideration :- It also will depend on the passenger and goods load, prop being used, petrol octane, wind, water conditions and how hard the RIB is inflated.

NB. In the "Liferaft Topic" a 9.9 HP O/B on a 10ft RIB was exampled :- At 0.99 gallon per hour its 5 gallon tank would have lasted at full throttle = 5 hours 3 minutes. Even at 2 knots they would have covered the 5 miles with ample fuel left in the tank.

Richard

[Footprints]

One good test is to put one gallon, maintain a specific acceleration with out any throttle variation and see how much time you run till the engine stops.

Richard,

I would suggest while conducting this test you circle the mother ship, other wise it could be a long paddle back to the boat!

[MMNETSEA]

Originally Posted by Footprints

Richard,

I would suggest while conducting this test you circle the mother ship, other wise it could be a long paddle back to the boat!

Sneaky solution - another hidden tank !!! Also take additional Roman rowing slaves.

Richard.

[Lynx]

that is really hard to say given wind, sea, load including any water, temp. One would suggest that you take a windy day, loaded it with about 9/10 full load including yourself and put 1 gan in the fuel tamk and motor into the wind and waves. Have a hand held GPS with trip log and extra fuel. You will then know.

The other question is - how big of seas can a RIB take? Better than no boat.

What is the biggest seas that you have been in with your dinghy?

Me, about 3 feet in my 8 foot Portland Pudgy.