RIBnet Forums

RIBnet Forums (http://www.rib.net/forum/)
-   Engines & props (http://www.rib.net/forum/f36/)
-   -   2 - 2.5 Gallons per Hour (Not) (http://www.rib.net/forum/f36/2-2-5-gallons-per-hour-not-846.html)

seafariskye 28 May 2002 15:23

2 - 2.5 Gallons per Hour (Not)
2-2.5 Gallons per hour???????

I think you may have been listening to the salesman to much.

The day any 120hp, inboard or outboard, petrol, or diesel uses that little amount of fuel, is the day not only the cows come home, but they will pass you swimming.

Dream on, i had a flymo that used more than that, and i was pushing it along!!!!!!


Mike C 28 May 2002 17:16


Yes, I have trouble believing it too.... which is why I said wait till August when I'VE tried it but these are apparently EP Barrus official figures, and I've spoken to at least 3 other people, apart from residents of Hull and not all salesmen, who seem to agree. Maybe it was downhill!

And we always believe official figures, don't we boys and girls?:rolleyes:

Mike C

seafariskye 28 May 2002 18:26


Official figures - you go to as show, which is where we all like to go to get the 'true' answers, be it from Volvo, Honda, Yam etc etc, you never get the really, really true figure.

On engine price yes, but the rest no,,,,,, sorry to be so un reassuring, but it is true.
Ask the guys that have bought them, they will tell you, the double look all these guys are having at their flow meters tell all.

My fuel figures are up on what i thought, and i am buying diesel at 16p a L?

OK if using for an hour or 2 a month, but for any more than that, think very carefully.


Mike C 29 May 2002 18:18


Yes, I have been investigating this. The figures I had been given, turned out not to be Barrus figures but Sowester trial figures in an actual boat. The true Barrus figures are much worse, around 24 Litres per hour at WOT, but that's under full load on a test bed.

The confusing thing is that, in addition to Hull residents, I have spoken/communicated with, 3 people with the Mercruiser 1.7, (only one of whom was a salesman), and they do seem to agree at about the 2 GPH figure. However, this is an average figure including slow running too. I suspect the true figure will be disappointing but it has to be better than the 2 x 60 hp 2 strokes I had before. They used 100 litres total from Poole to Cherbourg. I'll let you know what the Mercruiser does…... eventually!

Investigations continue, but in the meantime, anyone with the Mercruiser 1.7 TDI.... Any comments?

Mike C

Mike C 31 May 2002 19:42


Adding to the confusion, there is a magazine article I came across, (directed by a ribnet message) at http://www.askeladden.no/vis_omtale....leID=62&Page=3
This gives running details of the 1.7 in a 6.45 Mtr cabin cruisery thing called an Askeladden Beetle. (Heavier than a similar sized RIB I would think). There is a full report. Unfortunately it's in Danish.

The relevant bit reads..... "Pá fladt vand med to mand orn bord præsterer Mercruiser maskinen en tophastighed pá ca. 30 knob. Motoren opgives at forbruge 12 liter i timen ved 3000 o/m. Her sejler Askeladden Beetle godt 18 knob, med et forbrug pá ca. trekvart liter pr. sømil."

This, translated by a good friend of mine in Norway, (same sort of area!) reads

"On calm water with two men onboard the Mercruiser engine has a top speed of about 30 knots. The motor uses 12 litres an hour at 3000rpm.
Here, the Askeladden Beetle is sailing at a good 18 knots using three quarters of a litre per sea mile."

Also do a ribnet search for 'MerCruiser D1.7L TDI'. There is some interesting reading. I don't really believe 2-2 ½ GPH either... but they can't all be wrong? :eh:

How much did you say you paid for your diesel?

Mike C

seafariskye 17 June 2002 20:30

Chew and work this out!!
Back to the figures to scare you (if my maths are correct)

I have recently used 225 L for 12 hours - very easy running- with a 170hp diesel inboard:
which means basically 4.1 gallons per hour?
Working towards the mercruiser 1.7 diesel(in a roundabout way)
The SOC are using 1,315L over 760 miles, divide this by 2 and you end up with 120hp - the mercruiser??

Then works out as 0.9L per mile - 10 miles = 9 L of fuel/hr

Therefore at around 20knots you will be using 18L = 4 gallons of fuel per hour- considering this is less than the 'average' speed all else will be travelling at I reckon the figures for this engine are complete nonsense.
Ask the round scotland crew and see what they say??

The salesman has the best figures - because he never puts the £ in the tank??

My Flymo still uses more- sort the fuel figures out before you buy!



Mike C 18 June 2002 20:02

Thanks Pete,

I'll pop out and buy a calculator and get even more confused!
I'm not going to dispute anybodies figures. I am picking up my new boat around the middle of July and hope to have it in the water by the end of that month. When I'VE tried it, I'll know but what ever the figures, it HAS to be less than I got for my twin 60hp two stroke set up, which only got about 3 - 3½ gals per hour on average for EACH engine!
Anyway, if you say you got 4 gals per hour for the 170 hp diesel you were running, then around 3 gals per hour, (which I think may be more accurate), would perhaps seem to tie up for the 120hp Mercruiser? I'll be very happy with 3 especially at 30p per litre, (at least for the time being)
The proof of the pudding will be eaten in August. :lick: Watch this space!

Mike C

All times are GMT -5. The time now is 02:09.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.