Fuel consumption

jellifish · 12 July 2008, 19:38

Ive recently brought a 4.7 humber assault. Great fun, but was wondering about fuel consumption. Have a 60hp Mariner bigfoot 2 stroke, was surprised that I used £20 worth of petrol in an hour and a bit. Was restricted to 6 mph speed limit, wondering how many miles to the litre, I should be getting. Oh alright laugh! knew it was an expensive hobby but not THAT expensive. Just had engine serviced so should be running at optimum level. Appart from losing weight ! any suggestions. Thanks
John

Steve_B · 12 July 2008, 20:36

6 mph is about the worst speed you can do in a Rib. You will be pushing a big bow wave ahead of you and be using about 50% throttle.

These boats perform best at planning speeds, so get out of that restricted area and let her have some real throttle. Once your over the "hump" and planning you can bring back the throttle to about the same as you were at 6mph and will find your doing 20kts or there abouts and your fuel use for a given distance vastly improved.

Good luck

jellifish · 12 July 2008, 20:51

Hi yeah thanks for this. I know its a very low speed, but took it out on the local river just to get used to it, so hense the restriction on speed. Don't intend to use it there in the future, glad consumption will be better when opening her up. Saving up for next trip already!!
Thanks
John