fuel consumption?

[anthony]

Does anyone know what the fuel consumption would be on either 15hp or 25hp 2 stroke engine?

[Turbodiesel]

A 25hp will use approx 8.3 litres an hour at wide open throttle.

A 15hp will use approx 5 litres an hour at wide open throttle.


The usual rule of thumb is the HP divided by a third for a carb 2 stroke.
For an opti of four stroke divide the figure by a third again. And its always per hour at wide open throttle.

[hard1]

Eh? You're saying that my Opti only uses 25 litres an hour at WOT? Let me see, that's 8 mpg!

I'm deffo not selling it now....

[Hugh Jardon]

Originally Posted by anthony

Does anyone know what the fuel consumption would be on either 15hp or 25hp 2 stroke engine?

buggerall...

you can spin around all day, go here go there and back again, fast and slow, donughts, jumps etc etc and it will hardly use a sniff of fuel. I have a 15hp on a 3.4 quicksilver and you are lucky to use half a 25 litre tank a day, hardly worth the worry unless you are trying to calculate how much fuel you need to do a certain distance.

not sure if that helps but they hardly use anything on such a boat

[Hugh Jardon]

Originally Posted by hard1

Eh? You're saying that my Opti only uses 25 litres an hour at WOT? Let me see, that's 8 mpg!

I'm deffo not selling it now....

can i buy your opti pleassssssssssssssssssssseeeeeeeeeee..

[Mollers]

Why is there so much banging on about fuel consumption?! Unless you are a commercial user, boats are a luxury. One must have disposable income to even consider one.They cost to buy and they cost to run. Big engines burn more than small, correspondingly big boats cost more to run than small. Fuel is very expensive in the UK. My point is, in terms of overall cost of ownership and running costs the difference between a slightly more econmical 4 stroke over a 2 stroke is not worth worrying about. The servicing, marina, insurance, depreciation etc will make the fuel cost over the length of ownership pale into insignificance. If your spending money on fuel it means that the boat is being used and you're really getting some value out of it. So, if you're gonna worry about fuel, perhaps you should think of another less expensive pastime. In my opinion!

[Hugh Jardon]

Originally Posted by Mollulnan

Why is there so much banging on about fuel consumption?! Unless you are a commercial user, boats are a luxury. One must have disposable income to even consider one.They cost to buy and they cost to run. Big engines burn more than small, correspondingly big boats cost more to run than small. Fuel is very expensive in the UK. My point is, in terms of overall cost of ownership and running costs the difference between a slightly more econmical 4 stroke over a 2 stroke is not worth worrying about. The servicing, marina, insurance, depreciation etc will make the fuel cost over the length of ownership pale into insignificance. If your spending money on fuel it means that the boat is being used and you're really getting some value out of it. So, if you're gonna worry about fuel, perhaps you should think of another less expensive pastime. In my opinion!

sorry mollers, i have to think economy, that is why i switched to a economical v8.......actually true

mind you the idea of an opti devouring 19.5 galls per hour is a worry

[Mollers]

Originally Posted by Hugh Jardon

sorry mollers, i have to think economy, that is why i switched to a economical v8.......actually true

mind you the idea of an opti devouring 19.5 galls per hour is a worry

Once you've frightened ya'self witless in that Vipermax Turbonutter thing that you're proposing, you'll be tootling around at 40 gph!!

[Mollers]

Hang on, it was the Cobra Turbonutter or the Addernutter Turbo? Some F'ing fast snakey thing anyway!! Got me back peddlin' boots on.

[Hugh Jardon]

Originally Posted by Mollulnan

Hang on, it was the Cobra Turbonutter or the Addernutter Turbo? Some F'ing fast snakey thing anyway!! Got me back peddlin' boots on.

i was thinking a pair of nice 7.4 v8 inboards but the mrs pointed out they would be "cant see me girls" so perhaps a pair of 275 see me girls would be better. just thinking what i can sell to get a a see me girls, hmmmmm

anyway i need to go and put some fires out now, ive got me hose ready!

sseeee ya

[Rodan]

Originally Posted by hard1

Eh? You're saying that my Opti only uses 25 litres an hour at WOT? Let me see, that's 8 mpg!

I'm deffo not selling it now....

You sure???? Mine is happy to gently sip away at 22 Gallons per hour WOT... same engine! You sure your litres are not smartcraft gallons?

[Turbodiesel]

Sorry, A bit missleading on the OPTi and Four stroke figures

Example

A 200Hp carb will use Approximatly 66 litres an hour at wide open throttle.

So a 200hp OPTI will use a third off that figure again. Third of 66 is 22 litres.

Take 22 from 66 gives you 44 litres an hour.


This is only used as a guide so no one start saying how wrong it is . Always depends on the boat and load in the boat etc etc.

God just read all that, sounds like a maths lesson!!!!

[Hugh Jardon]

Originally Posted by Turbodiesel

Sorry, A bit missleading on the OPTi and Four stroke figures

Example

A 200Hp carb will use Approximatly 66 litres an hour at wide open throttle.

So a 200hp OPTI will use a third off that figure again. Third of 66 is 22 litres.

Take 22 from 66 gives you 44 litres an hour.


This is only used as a guide so no one start saying how wrong it is . Always depends on the boat and load in the boat etc etc.

God just read all that, sounds like a maths lesson!!!!

if a boat has a 200 opti fitted, will the fuel used depend on the boat it is fitted to even if the throttle is wide open?

most people report the fuel smart craft as showing around 19-20 gals per hour at max throttle position which i make to be 19x4.54 = 85+ litres per hour

do you think your estimates are more accurate?

do you know if the smartcraft gauges read in us or imp gallons?

cheers

[Mollers]

Originally Posted by Hugh Jardon

if a boat has a 200 opti fitted, will the fuel used depend on the boat it is fitted to even if the throttle is wide open?

most people report the fuel smart craft as showing around 19-20 gals per hour at max throttle position which i make to be 19x4.54 = 85+ litres per hour

do you think your estimates are more accurate?

do you know if the smartcraft gauges read in us or imp gallons?

cheers

A 200 Opti will burn the same amount of fuel at WOT regardless of the boat it's attached to. What will alter greatly is the speed that it'll be travelling at.

[Andy Moore]

Originally Posted by Hugh Jardon

do you know if the smartcraft gauges read in us or imp gallons?

Can the SmartCraft guages read out in whatever units one requires? (ie Imp Gals, litres)

[Hugh Jardon]

Originally Posted by Andy Moore

Can the SmartCraft guages read out in whatever units one requires? (ie Imp Gals, litres)

As no one seems to know if the gals displayed on smartcraft are imperial or us gallons, or at least noone has responded to that question when i have asked it with an authoritive yes or no.

i have done some research and the options are as follows

metric litres
or gallons english (us)

so

when your gauges are reading 19.5 gals at WOT you are actuall using 16.2 uk gallons

1 us smartcraft gallon is 0.833 uk gallon

i have downloaded the complete manual set from mercury on the smart craft operations manual for both smartcraft gauge combinations

http://www.mercurymarine.com/uploads/images/914/10229023.pdf

the smartcraft gauges can do a heck of a lot so i suggest downloading the manual and have a play as lots of useful features.

hope you opti users find this useful

chris

[Nos4r2]

Its far easier to use the yank method-fuel consumption=10% of HP in GPH...and anything better than that's a bonus.

[Andy Moore]

Originally Posted by Hugh Jardon

metric litres
or gallons english (us)

So you can set them to read out in litres per hour? If so, that's problem solved isn't it?

[hard1]

Originally Posted by Nos4r2

Its far easier to use the yank method-fuel consumption=10% of HP in GPH...and anything better than that's a bonus.

I'd go with that one. Sounds a lot nearer the mark.