fuel consuption in rough sea

[narooma]

Two questions on fuel consumption for any out there who know about these things.

1. Does fuel consumption increase for the same revs when going into rough seas as against flat ?

2. I noticed a boat similar to mine for sale where the engine was quoted as giving 1.25 ltr/hr. The engine was a 12 yr old Perkins sabre 125 h.p.

Mine is a Perkins 6354 115h.p, 20 years old and does 6.25 ltr/ hr.
Is mine using too much or the other stretching the truth a little?

 

[alan006]

Just answered your question on the rag and stick forum. /forums/images/graemlins/laugh.gif /forums/images/graemlins/smirk.gif

 

[colvic987]

nil litres per hour for me, don't seem to use the engine in rough seas, as there is normally to much wind to use.. /forums/images/graemlins/confused.gif

 

[bedouin]

1. Yes definitely - if the engine is working harder then it uses more fuel.

2. There won't be that much difference between the consumption of two similar boats - and yours sounds about right. I wonder whether the other guy was confusing litres and gallons /forums/images/graemlins/smile.gif

 

[MM5AHO]

depends on how you measure fuel consumption. volume per time or volume per distance?
litres per hour not that much different in my experience, but kilometres per litre much reduced into rough weather.

 

[ebbtide]

Re: fuel consuption in general

Your Moody Carbineer, like all yachts, will be economical simply because you can't do much more than 7 knots, can you?
My consumption (same engine in 28ft semi-displacement MoBo ) is similar at that sort of speed. In fact over the last 3 years (800 hours) it is consistently under 8 litres/hour when cruising. Ambling up a river at 4 knots halves that figure, planing at 12 knots will increase it by 50% - as does bashing into rough seas when 7 knots is comfortable.

Do PM me if I can help further.