Fuel consumption - twin diesel engines

[Roadhog]

Can anyone give me any figures (LPH/GPH or n-MPG) just averages/rough guide on a 30ft Flybridge with twin 200hp Tdiesel Yanmars? Also is there a Fuel calc program on a website anywhere? I understand there are lots of factors - weight, conditions, speed etc. that change things But any figs would be useful - thanks.

 

[Whitelighter]

Useful fuel calcilater at www.passageplan.co.uk - though it is just a rough approximation because as you say, there are many influencing factors.

You dont say the age of the boat/engines either. Modern DI engines are much more efficient than the older mechanical injection units. As rough pointer, I would expect around 65lt/hr at 25knts.

 

[Divemaster1]

When you take out approx 75% of the engines (that is HP, not RPM .... but my guess ist that it will be 3-400 off the top .... if it is a high rev engine)... you'll end up with approx 300 hp outtake..

300 hp @ 200 grammes per hp/hr (sort of OK calculation base for average diesel engine) ... gives 60 kg fuel per hour

Diesel have a weight at about 0.86 kg / L...... so you end up with approx 70 L per hour ...

So it all depends on what HP you take out of the engines really ....

 

[Roadhog]

They are 2003/04 vintage. Thanks for info so far...

 

[[2068]]

My twin 170hp diesels burn about 45litres an hour at 22kts. That's on a slightly smaller boat, a 29ft sports cruiser.

dv.

 

[hlb]

KIS, mine does a bit beter than 1 MPG. so some where between that and 2.

 

[omega2]

With our twin 180's ford sabres, we have long since stopped worrying about fuel consumption, suffce to say we are contributing to global warming in a big way. If you have to worry about how much you cannot afford it.

 

[oceanfroggie]

<u>39ft Broom SD hull - 2 x Yanmar 260HP</u>
7.5kt @ 2gph - displacement speed = 3.8mpg, range 750nm
15kt @ 10gph - economic cruise = 1.5mpg, range 300nm
20kt @ 15gph - cruise speed = 1.3mpg, range 267nm

 

[[2574]]

Faorline Targa 39; twin 230hp KAD43 - 1.2mpg long term average cruising at 22kts.

 

[Andrew_Fanner]

Two HT6354s, 5.8l each, 8gph at full chat, each. Won't be doing that post 1/11/08 Usefully less at river speeds and may just be affordable on homebrewed bio.

 

[apollo]

Half a gallon per hour per engine on the Upper Thames.

 

[neale]

Depends if those Yanmars are on shafts or drives. Drives are more efficient but the savings are eaten into by the extra servicing costs. I would expect 1.something mpg on shafts and possibly around 2ish mpg on drives.