Engine hours

[MapisM]

Wait a minute in post # 49 with the "AOTBE " is assumed the 9 knot vs 24 knot was in the same boat hull -why wouldn,t I?

Well, by AOTBE I actually meant all other RELEVANT things being equal.
I don't think the hull where a engine is installed is so relevant in this context, other than sort of implying that the same engine installed in a P boat is likely to have worked harder than in a trawler, for any given amount of running hours.

But let's stick to the same hull, if you prefer.
I'm sure you will agree that you are adding a lower amount of wear and tear to your engines in your boat after one hour of at 9 knots, compared to one hour at 27kts.
And even if you wish to compare the distance cruised rather than hours, even if I don't know the exact numbers for your boat/engines, obviously you would burn less fuel in three hours at 9 knots than in one at 27.

That's all I was saying: I'm not pretending that fuel burnt is the be–all and end–all criteria, but it's much better than hours anyway, regardless of how popular the latter is vs. the first.

 

[MapisM]

For the avoidance of doubt my boat is sterndrive.

LOL, yeah, of course. Just imagine accessing the g/box at the back of your engines...!
And btw, outdrives without a g/box do exist (though VP doesn't build any, afaik), so the problem is not just academic.

 

[Portofino]

Well, by AOTBE I actually meant all other RELEVANT things being equal.
I don't think the hull where a engine is installed is so relevant in this context, other than sort of implying that the same engine installed in a P boat is likely to have worked harder than in a trawler, for any given amount of running hours.

But let's stick to the same hull, if you prefer.
I'm sure you will agree that you are adding a lower amount of wear and tear to your engines in your boat after one hour of at 9 knots, compared to one hour at 27kts.
And even if you wish to compare the distance cruised rather than hours, even if I don't know the exact numbers for your boat/engines, obviously you would burn less fuel in three hours at 9 knots than in one at 27.

That's all I was saying: I'm not pretending that fuel burnt is the be–all and end–all criteria, but it's much better than hours anyway, regardless of how popular the latter is vs. the first.

Yes all understood -but which boat would you buy AOTBE - just to clarify I mean that absolute -equal same hull ,marque ,modal -same age ,condition , engines ,price ,colour ,spec -identical except one tiny detail = Hrs

So as per your example diff hours by a factor of 3
One has x hrs t,other has 3 x
400 Vs 1200 hrs
900 Vs 2700 hrs

just to tie up one more variable to clarify if it was my boat as you ask and we can use those numbers ?
Loosely 9 knots for 3 hours burns 100L whereas 27 knots for one hour will be 200L - so low hrs faster boat has had twice fuel mass through it .

The two boats are moored side by side .

Which one will sell 1st the low hrs or 3x hrs ---? ------- and ps offer up an explanation for your reason .-remember both logs state same distance covered .
Many thanks in anticipation MapishM

 

[MapisM]

Which one will sell 1st the low hrs or 3x hrs ---? ------- and ps offer up an explanation for your reason.

That's a very easy question: the low hours will sell first, because that's what the market look at, mostly.

But if you ask ME, assuming that I would know for sure that the higher hours boat burned half of the fuel burned by the low hours boat (and that age, maintenance etc. are all the same), I'd have the half-drinker-triple-hours for good.
The reason being, quite simply, that I put my money where my mouth is. If I'm convinced that fuel burn is a better indicator of engine wear and tear than the hours, why on earth should I buy the low hours boat?
Unless of course I would want to resell her soon, in which case my first reply to your question could drive my choice, rather than any technical consideration.

 

[Deleted User YDKXO]

That's all I was saying: I'm not pretending that fuel burnt is the be–all and end–all criteria, but it's much better than hours anyway, regardless of how popular the latter is vs. the first.

Agreed. Another major determinant of engine wear is the number of cold starts and you can get some idea of that by asking what kind of boating the previous owner did. Two boats may have similar hours/fuel burnt but if one has been used mainly for day trips only and the other mainly for extended cruising, the former is likely to have experienced a much larger number of cold starts and AOTBE its engines are likely to have experienced greater wear

 

[MapisM]

Absolutely agreed.
But while the lifetime fuel burn can be easily checked in modern electronic engines, I have never seen engine cranking stats in any engine display - and it's hard to make a comparison just based on the previous owner(s?) impressions...
Glad to stand corrected if anyone knows better, though!