Fuel Consumption

Biggles · 20 August 2006, 21:15

At the risk of starting a war.

Would a 135 HP Optimax have worse fuel consumption than a 4 stroke of the same HP ?

Searider · 20 August 2006, 21:51

As long as you keep an Optimax below 4000rpm they are great on fuel.
I get about one mile per litre up to about 28/30 knots.

Rogue Wave · 22 August 2006, 02:24

Hi nick

I've justmanaged to convert Ben from 4 strokes to 2 strokes Ask Him.

I don't think theres much in it at all

benc · 22 August 2006, 09:04

I went for bigger engines than before, but at 40 knots, im saving money, 30 knots is about the same... I wouldnt say the "new technology" two strokes are any thirstier than the equivilent 4/stroke.

They do smell a bit more though

Rogue Wave · 22 August 2006, 10:41

I love the smell of 2 stroke in the morning

eupa · 22 August 2006, 11:08

I love the smell of 2 stroke in the morning

It shure does something to you.. dont know exactly what?. smells more professional

Jonathan

Lostboy · 22 August 2006, 22:16

Quote:

Originally Posted by Searider

As long as you keep an Optimax below 4000rpm they are great on fuel.
I get about one mile per litre up to about 28/30 knots.

28 l/hour? Blimey, I know that the 115 on a Leeway 600 is averaging 10l/hour and my Evinrude (ficht) DI 115 on the same boat is doing the same.

Pete7 · 23 August 2006, 08:22

Quote:

Originally Posted by Lostboy

28 l/hour? Blimey, I know that the 115 on a Leeway 600 is averaging 10l/hour and

At what sort of speed though and therefore what would the mpg for the Evinrude be ?

Regards

Pete

tcwozere · 23 August 2006, 09:14

Quote:

Originally Posted by Lostboy

28 l/hour? Blimey, I know that the 115 on a Leeway 600 is averaging 10l/hour and my Evinrude (ficht) DI 115 on the same boat is doing the same.

Judging by the whiff of fumes in the air from the one parked up at Clarence, I am guessing that 10l/hour is when its on a trailer??

benc · 23 August 2006, 09:17

My boat at the moment, is using 15l/hour at 6 knots , think it was about 10-12 before with the twin 115's

Searider · 23 August 2006, 13:02

What I meant to say was - more than a mile per litre up to 28/30 knots, less than a mile per litre over 30 knots.

I imagine my boat is a fair bit heavier than a Leeway 6m?

Lostboy · 23 August 2006, 13:05

Quote:

Originally Posted by tcwozere

Judging by the whiff of fumes in the air from the one parked up at Clarence, I am guessing that 10l/hour is when its on a trailer??

Ha ha!!! Slight issue yesterday with a fuel pipe under the cowling. Halfway through mine and the kids PB2 course!!! (Talking of which I can wholeheartedly recommend Stormforce Coaching at Southampton!)

10l/hour is the average consumption from it's 15 month life with us. This includes a lot (50 hours+) of Portsmouth Harbour-IOW commuting for sailing, a few beach days, wakeboarding, towing inflatables etc. Most of it's use is at circa 4k revs (25 knots on the current prop).

Interesting consumption from the PB2 2 day course. With 4.5 hours of VERY slow speed (sub 6 knots) and 30 minutes of 20knots work on the first day it used 10.5l of fuel (I had the embarrassment of going through the Hythe lock to get that amount of fuel!!!) and in 4 hours of high speed work and an hour of sub 6 knots yesterday (the second day) it used 40 litres, giving it an average of less than 10l/hour for the two days!

benc · 23 August 2006, 14:09

That really does sound unbelievably cheap

Lostboy · 23 August 2006, 16:39

Quote:

Originally Posted by benc

That really does sound unbelievably cheap

I thought so but the fuel spreadsheet on the laptop (I haven't got anything hardwired on the boat, unlike the no. 2 boat) confirms it time and again. It shocked me so much that I asked both the guys with the no.2 boat and also Doug at Seaforce who has a later version with a 90 and does nearly as well!! Scarily good.

Tony, the other reason that my rib smelt recently is that I brimmed it and it shot a bit through the vent on trailer trip back to the marina!