fuel consumption

antiqueboy · 21 May 2006, 16:01

in my quest for a bigger and better boat, an idea of fuel consumption would be good as i dont want to over stretch in my need for speed. ie
from northeney, hayling island to cowes and back(40 miles?) on my medline 1 4.8 meter with 65hp suzuki i use about £40 flat out where possible.

what do others use use both petrol and deisel over a given distance.

Biggles · 21 May 2006, 16:11

Doing the same journey as you would cost me £20.

antiqueboy · 21 May 2006, 16:18

why do you think their is such a big difference, my engine is 2 stroke, whats yours

Roy Smith · 21 May 2006, 19:17

Did Northney though the bridge to cowes and back over the bar
£51 at about 4500 to 5000 knts

ashbypower · 21 May 2006, 19:35

Quote:

Originally Posted by Roy Smith

Did Northney though the bridge to cowes and back over the bar
£51 at about 4500 to 5000 knts

Biggles · 21 May 2006, 20:24

I do that journey regularly. I have a four stroke 50 HP and keep it about the 4000 RPM mark. I have a 25 Litre tank and I don't use all of it on that journey.

I go up to 5000+ Revs on the odd occasion but find 22 Knots at 4000 is ample. Cheaper on fuel and got to be good for the engine. Plus it means I don't stuff it so often.

fjarvis · 21 May 2006, 20:33

I can get about 50 miles from my 22Lt tank when cruising with an RPM of around 4000-4500.

Cheers,
Fraser

Biggles · 21 May 2006, 23:59

As much as I know people love 2 strokes on this site in their different variants with my limited knowledge I have found my one and only 4 stroke so far to be absolutely wonderful on fuel consumption.

At the end of the day a 50 HP 4 stroke has as much power as a 50 HP 2 stroke. They are both 50 HP.
The 50 HP 2 stroke is cheaper to buy brand new, is lighter but to someone like me is no cheaper to service. I can change plugs, oil and possibly an impellar. I can't do the cam belt but I also can't muck around with reed valves etc.
For me 4 stroke is the only way to go.

Go on give it a try you know you will love it.

Biggles · 22 May 2006, 00:01

Quote:

Originally Posted by Roy Smith

Did Northney though the bridge to cowes and back over the bar
£51 at about 4500 to 5000 knts

I would pay that to be on a 8 metre boat with a group of friends but I wouldn't want to pay it if I was on my own for a bit of a muck around twice or three times a week.

benc · 22 May 2006, 07:35

Quote:

Originally Posted by Roy Smith

Did Northney though the bridge to cowes and back over the bar
£51 at about 4500 to 5000 knts

Not a bad speed for the money!

On a serious note, I don't think I would use that much in mine, maybe about £40 or so.

Carl · 22 May 2006, 08:04

Quote:

Originally Posted by antiqueboy

in my quest for a bigger and better boat, an idea of fuel consumption would be good as i dont want to over stretch in my need for speed. ie
from northeney, hayling island to cowes and back(40 miles?) on my medline 1 4.8 meter with 65hp suzuki i use about £40 flat out where possible.

what do others use use both petrol and deisel over a given distance.

xr2 from northney to cowes and back £70 plus oil £15

BogMonster · 22 May 2006, 11:52

Couldn't say in terms of miles per gallon but the fuel consumption on my 115 is scary at higher speeds, cruising at 18-20 knots not too bad, go to 25 and it seems to more or less double, go to 30+kt and it seems to double again!!

The tank on mine is about 80-90 litres I would guess (never emptied it completely but have put 60lt in when showing about 1/4 full on the gauge) and I have used 1/4 tank in an hour and a half pottering round mostly at 10-15 knots then another 1/4 tank in about 20 minutes at "yeeha" setting

If I ever had to replace the engine, or ever got another boat, I think I would go for a four stroke on the basis that it must be more efficient (hard to be any worse!!) and the fact that I don't really like 2 stroke engines anyway

Under the Thumb · 22 May 2006, 16:29

Last trip out, was Felixstowe to Snape and back, approx 42 miles with lots of blasting in waves. used just over £40 of fuel and hardly any oil. cruising at 35kts

After having an Optimax i wouldn't want anything else

Hugh Jardon · 22 May 2006, 17:21

i appear to have the same consumption figures as yourself, using around a litre of fuel per mile but i suspect my oil consumption will be a lot lower given the total absense of smoke from my engine, from a smoke point of view you would think it was a 4 stroke

and that will b cruising around the 35-40 knots range

is a 200 hp opti on a vipermax 6.5

Quote:

Originally Posted by antiqueboy

in my quest for a bigger and better boat, an idea of fuel consumption would be good as i dont want to over stretch in my need for speed. ie
from northeney, hayling island to cowes and back(40 miles?) on my medline 1 4.8 meter with 65hp suzuki i use about £40 flat out where possible.

what do others use use both petrol and deisel over a given distance.

Rogue Wave · 23 May 2006, 08:33

The two strokes people seem to love on this site are usually new tech 2 stroke and they are great engines. I still think the best engine around is the three pot Yamaha two stroke range (60 -90) but thay can be a bit thirsty.

I chartered an old Yammie 250 2 stroke engined rib last week. Drove 5 people about twenty miles and had about 4 miles of one to one ....... Fuel Bill 93 pounds and 22 pence and that was from a garage not a pontoon. So big old two strokes are not able to compare with 4 strokes.

I've run Opti 150's and 225's and I feel fairly certain that the 150's are more frugal than the 225's ( on a LPH:HP ratio)

Having said all that I manage a floating Jacuzzi (Zebidee) which has a 75 merc 4 stroke and that gets to Yarmoth and back on about 30 litres and that is most impressive

Biggles · 23 May 2006, 18:20

Rogue wave,

I was also impressed with the consumption on Zebedee. Do you know if all Mariner 75 4 Strokes are like that.

Rogue Wave · 23 May 2006, 21:01

I think they probably are Nick, but it depends on boat weight and design also. put that engine on a boat that's a couple of hundred kilo's heavier and the consumption will go to pot.

Interestingly enough I believe that block and gearbox is the same as Benc has on his Tornado, which is a tammie 115. I think they run it at 75 with carbs and 90 100 and 115 with injectors. I am not sure cos I haven't looked at outboard brochures since i got a copy of the Cromwell catalogue. ( and that really is tool porn of the highest calibre ) No you can't borrow the catalogue not even Mark halliday is ready for that much stuff!