Draco 23

[Guest]

I am thinking of buying a Draco 23 with a Mercruiser 5.7ltr petrol, how much fuel willit use, how much will it cost to insure, is there a web page.

 

[Guest]

LOTS !

 

[Guest]

If my memory serves, they used to say you should reckon on 10-12 gallons an hour per 100bhp for a petrol engine at full throttle (we had a Fairline 21 with 211bhp Volvo and it drank the stuff like there was no tomorrow!)

 

[Guest]

Re: Thats a bit high

The rule is 5-6 Gph for a diesel and 7-8Gph per 100Bhp for petrol, that means your 200bhp Volvo crusied at 10-12GPh at just under WOT I would guess, 8-9gph would be average for a boat of this size at about 20-25knots cruise I would say.

 

[Guest]

no \'rules\' but just from my own experience...

Our Nimbus31 with 200hp turbodiesel uses about 7gph flat out (24 kts) and 4gph cruising and the Fairline21 with 211hp Volvo V8 petrol (at 35kts) used at least 14gph and cruised at about 10gph (28kts).

By your figures an inefficient diesel would be barely more economical than a good petrol engine and I haven't seen any test figures for big inboard engines in the magazines to verify that at all.

 

[Guest]

Re: no \'rules\' but just from my own experience...

Hang-on simple maths here, I said 7-8 Gph/100BHp petrol so for a 200Bhp thats 14-16gph, thats what you said your Fairline did flat out, so for a rule of thumb I would say thats pretty close. You originaly said 10-12Gph /100Bhp for a petrol, so thats 20-24Gph for your Fairline, a big difference I would say. Sorry to sound picky! Your Nimbus does sound particularly economical, possibly the 200Bhp is rounded up a bit, but single engined boats are very efficent, your Nimbus would certainly be on my next boat shopping list. Nearly all the boat tests I have read in MBM seem to indicate 10Gph for a 200Bhp Diesel, so the rule of thumb seems to work, but then test boats are always very lightly loaded. I think what kills it for petrols is the fuel used to accelerate onto the plane and the varying loads, where the petrol uses more fuel at the same rpm. A diesel because of its almost fixed fuel flow rate per rpm is much easier to predict.

 

[Guest]

Blame it on my Monday maths if you like!!

BTW - another Nimbus31 owner who is also an airline pilot and logs everything reckons on 4gph overall including some cross-channel cruises and river meanderings (Hamble, Beaulieu etc.) and our boat is shortly going up for sale as we don't have the spare time we would like to really enjoy it anymore.