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Adam Younger
09-24-2007, 03:09 PM
Hoping for some help with fuel consumption figures as manufacturers are next to useless with accurate info - over here (in UK) anyway.

I'm putting a team together to race in the 2008 Round Britain race - using a new boat of my own design (my job). She will be twin outboard powered and looking most likely at the 300 Verado's or maybe the 300 E-tecs when they come out.

Longest legs are going to be around 250 miles - so going to be a lot of fuel. We will be running a 32' stepped hull RIB, top speed in region of 80 mph - so as you can see fuel figures are pretty important to fitting tanks in / range / speed etc.

Any help appreciated!

ghind
09-24-2007, 10:26 PM
250 miles, 80 miles per hour top speed.

The all publish WOT fuel consumption figures don't they? Anyway, expect it to be about 30 gal/hr with a 300hp engine, holds pretty much true with any technology, carby, dfi, four stroke, whatever. At reduced throttle, some are more efficient, but at WOT, all are close enough for this rule of thumb.

250mph/80m=3.125 hours. 3.125 * 2 engines * 30 = 187.5 gallons. 10% extra, call it 220 US gal. You may use more in rough water so 250 US gal.

Best that you check the WOT fuel consumption of the engine you want. Be careful though as some motors claim to burn less but it is often because they make less HP than the one that uses more.

I've heard you might expect a DFI engine to be 10% more fuel efficient at WOT than a carby two stroke. Anybody got any experience?

STV_Keith
09-25-2007, 01:25 AM
FloScan will be your friend. :)

electricjohn
09-26-2007, 04:51 PM
1/2 of your horsepower divided by 6.23= GPH. This is just a rule of thumb.