guesstimate fuel

[JSP]

How many Nautical miles would you guesstimate an old 115hp V4 would get out of 50 litres at cruising speed?

[chewy]

Roughly 25 miles if your burning 11 gallons an hour which works out at roughly 50 litres per hour.

[Polwart]

Originally Posted by chewy

Roughly 25 miles if your burning 11 gallons an hour which works out at roughly 50 litres per hour.

I would hope more than that... most folk reckon on 1 US gallon (3.8 L) for every 10 HP on an old tech engine at Wide Open Throttle.

So 11.5 US gal per hour at WOT.
= 43.7 L/hr
So 50 L would last about 70 mins

At WOT I am guessing JSP will be doing 35 knots ? - So Would expect around 40 nm.

At cruising speed possibly a bit better.

[J S]

Yes id say more like 35-40 miles. So 0.7 - 0.8 miles per litre.

James

[Nos4r2]

I'd say try it and find out. There's too many variables for a safe guesstimate unless you actually own the boat...

[chewy]

Didn't realise it was US gallons.

Are you running 2 25 litre tanks? Just see how far you get on one and double it.

[JSP]

Yeah 2X25L tanks.
Just trying to work a rough guess.

[Downhilldai]

My V4 Soozook DT100 burns around 1 litre/nm at cruising speed (28ish kts) on a similar size boat. Your Yam may be a touch thirstier, but there shouldn't be much in it.

[JSP]

Originally Posted by Downhilldai

My V4 Soozook DT100 burns around 1 litre/nm at cruising speed (28ish kts) on a similar size boat. Your Yam may be a touch thirstier, but there shouldn't be much in it.

So going off that and Polwarts sums I should take it at about 35nm on the safe side from a 50L tank. I've only pished about in it so far, thinking of taking it from Preston to Fleetwood which is around 25 nm. If I work off that to start with and then I can see what I actually get. And if it seems to be using more I've got a couple of options to get fuel.
Cheers lads

[uncle al]

we used to say as a rule of thumb a third of the horse power in litres per hour st wide open throttle WARNING nobody can give you an accurate answer to this question as weather condition , boat , boat load there is a lot of factors to put into the equation