Update & Corrected Running Costs

[Mindi]

The intention was and still is to highlight the growing impact of fuel costs on our motor choices. It's not about bagging Etecs or 4 strokes...its about understanding the costs. The idea was OK I thought except I made a mess of the numbers. I cant attach an Excel spreadsheet to a thread here so the numbers are...

Running Costs over three years

If you do 50 hours/year

Suzuki 70/90........$3900
Etec 75.................$4311 ( +411)
Opti 75.................$5568 ( +1688)

If you do 100 hours/year

Suzuki 70/90........$6705
Etec 75.................$8172 ( + 1467)
Opti 75.................$9429 ( + 2724)

Happy to PM anyone who wants the spreadsheet. Of course this is only one factor in choosing a motor and does not take into account performance, original cost or resale value, or reliability...just week to week running costs

[two up]

Mindi,
great idea, how do you arrive at these figures. Is it simply the price of gas to run 50 and 100 hours and ( oil for 2 strokes ) service costs or is there something else in your calculations.

[Mindi]

Mindi,
great idea, how do you arrive at these figures. Is it simply the price of gas to run 50 and 100 hours and ( oil for 2 strokes ) service costs or is there something else in your calculations.


fuel, oil and service only. Based on 11.0 lph for a suzi 70 at 3500 and 14.2 lph for a Etec 75 at 3500 rpm, XD100 at $11.50 litre, fuel at $1.70 litre, and services as advised by three dealers. Consumption figures from manufacturers websites.

[Jabba_]

Mindi,,, are you still basing your fuel figures on liters per hour?.... If so, the out come is still going to be inaccurate.... You need to define an actual average distant traveled per year, and then calculated speed, distance and time travelled.... Example... I 80% off the time travel at 3200rpm @ 34mph @ 30ltr/hr, so it would take 2.9hr to travel 100mile and 87liters....

Say in with a differant motor (same boat) @ 3200rpm will do 25mph use 25lt and it will take 4 hrs to cover 100mile, and at that it will consume 100ltrs......

So you cant just base your maths on liter/hr... You need to define there cruise speed and at what rpm, and then there liter/hour

[uripper]

Mindi

Great topic - one Ive been contemplating for a while - as an owner of a late model 130hp 2stroke, none of the primitive number crunching I've done comes close to warranting a change over even at $2.00/litre - thanks for objectivity - will PM you for spreadsheet details

Mal

[Mindi]

Mindi,,, are you still basing your fuel figures on liters per hour?.... If so, the out come is still going to be inaccurate.... You need to define an actual average distant traveled per year, and then calculated speed, distance and time travelled.... Example... I 80% off the time travel at 3200rpm @ 34mph @ 30ltr/hr, so it would take 2.9hr to travel 100mile and 87liters....

Say in with a differant motor (same boat) @ 3200rpm will do 25mph use 25lt and it will take 4 hrs to cover 100mile, and at that it will consume 100ltrs......

So you cant just base your maths on liter/hr... You need to define there cruise speed and at what rpm, and then there liter/hour

Jabba
Not convinced by your argument for two reasons..

1. The whole thing is comparative rather than absolute...and the comparison will be accurate enough even if the 11 is really 9 and the 14 is really 12..?? The point is to see how a 4 stroke compares with a DI 2 stroke...


2. In any case litres/hour is (IMHO) more meaningful... as distance travelled over the ground is influenced by external issues like tide, current, weather etc etc ...running hours of the engine at a standard rpm is just that...running hours at a standard rpm...how far you go is not a relevant parameter....otherwise benchtests would be meaningless..?

[Outsider1]

Jabba
Not convinced by your argument for two reasons..

1. The whole thing is comparative rather than absolute...and the comparison will be accurate enough even if the 11 is really 9 and the 14 is really 12..?? The point is to see how a 4 stroke compares with a DI 2 stroke...


2. In any case litres/hour is (IMHO) more meaningful... as distance travelled over the ground is influenced by external issues like tide, current, weather etc etc ...running hours of the engine at a standard rpm is just that...running hours at a standard rpm...how far you go is not a relevant parameter....otherwise benchtests would be meaningless..?

I would have to disagree with you there Mindi.

Fuel consumption at a particular rpm level is not indicative of overall consumption, even on a relative basis.

I was reading Saltwater Fishing earlier and came across a response to a letter by their boating editor Andrew Norton to a question about best motor choice for a particular boat. Now in this case the motor in question was an E-Tec but could have been a number of brands. His comment was that the E-Tec would use much less fuel (than a 4 stroke) whilst trolling (over 50% less), but could use up to 15 to 20% more at cruise. Now there is one thing you can say about Andrew and that is he knows his fuel consumption info backward. I have copied the letter below so you can read it first hand.

I see lot of litres per hour fuel consumption figures quoted here and elsewhere that just do not gel. After thinking about it I have come to the conclusion that a lot of people are measuring overall fuel used against motor hours, not cruise speed usage. Why?, well most do not actually have the measuring devices and gauges to quote accurate cruise speed usage, so the only measure they have is how much fuel did I use, and how many hours did I run the motor for.

I kept accurate and detailed logs of fuel info on my old Johnson 150hp for years and it averaged out at about 12 litres per motor hour. Yet I know that at cruise it was more likely using 30 litres an hour!

Have you ever wondered why when you go on a long trip and travel at 100 or 110 kmh, that your average speed is only 80kmh?

I was watching a Top Gear clip earlier where they tested a Toyota Prius against a BMW M3 around a race track. The Prius was driven as fast as it could go and the M3 just shadowed it. The result; the Pruis used 17mpg and the M3 19mpg!

Not trying to be negative and I think the exercise you are attempting is very worthy, but I think that total fuel usage figures are a bit more complex than you have allowed.

Cheers

Dave

[Mindi]

I would have to disagree with you there Mindi.

Fuel consumption at a particular rpm level is not indicative of overall consumption, even on a relative basis.

I was reading Saltwater Fishing earlier and came across a response to a letter by their boating editor Andrew Norton to a question about best motor choice for a particular boat. Now in this case the motor in question was an E-Tec but could have been a number of brands. His comment was that the E-Tec would use much less fuel (than a 4 stroke) whilst trolling (over 50% less), but could use up to 15 to 20% more at cruise. Now there is one thing you can say about Andrew and that is he knows his fuel consumption info backward. I have copied the letter below so you can read it first hand.

I see lot of litres per hour fuel consumption figures quoted here and elsewhere that just do not gel. After thinking about it I have come to the conclusion that a lot of people are measuring overall fuel used against motor hours, not cruise speed usage. Why?, well most do not actually have the measuring devices and gauges to quote accurate cruise speed usage, so the only measure they have is how much fuel did I use, and how many hours did I run the motor for.

I kept accurate and detailed logs of fuel info on my old Johnson 150hp for years and it averaged out at about 12 litres per motor hour. Yet I know that at cruise it was more likely using 30 litres an hour!

Have you ever wondered why when you go on a long trip and travel at 100 or 110 kmh, that your average speed is only 80kmh?

I was watching a Top Gear clip earlier where they tested a Toyota Prius against a BMW M3 around a race track. The Prius was driven as fast as it could go and the M3 just shadowed it. The result; the Pruis used 17mpg and the M3 19mpg!

Not trying to be negative and I think the exercise you are attempting is very worthy, but I think that total fuel usage figures are a bit more complex than you have allowed.

Cheers

Dave

Good argument...you are basically saying that 3500rpm comparison is not able to be generalised up and down.........you may well be correct. I am assuming that the 3500 rpm figures are representative across the range. I must have another look at the original data to see what they look like at lower and higher revs. I must admit i find it hard to imagine why a DI motor would use less at trolling speeds than a 4 stroke..?
Nonetheless I was trying to give some dimension to the margin by which a 4 stroke might use less fuel. Certainly it is more complex, no dispute there, but distance over the ground is not useful because of external factors.
What you really need is (as you suggest) to be able to look at a whole of life log and say "I did 560 mixed engine hours and I used 5400 litres "

[Jabba_]

I'm not sure were you fish mindi, but in North QLD and most outside fisherman will compare fuel consumption by distance travelled / litre...
When I was at Mackey last year for the best fishing I had to head out past St Bee's and Keswick Is. That is a 25mile run by itself, so an ecomocal per hour motor is usless if it has a slow cruise speed, as it takes longer to get to the destination, so therefore it will use more fuel ... And in conversation we always talk about litres/distance,, litres/klm, and we only every use litres/hr to calculate litres/klm...
It might pay to start a poll and ask which is more relevant, liters/hour or litres/klm.......

[Mindi]

Good argument...you are basically saying that 3500rpm comparison is not able to be generalised up and down.........you may well be correct. I am assuming that the 3500 rpm figures are representative across the range. I must have another look at the original data to see what they look like at lower and higher revs. I must admit i find it hard to imagine why a DI motor would use less at trolling speeds than a 4 stroke..?
Nonetheless I was trying to give some dimension to the margin by which a 4 stroke might use less fuel. Certainly it is more complex, no dispute there, but distance over the ground is not useful because of external factors.
What you really need is (as you suggest) to be able to look at a whole of life log and say "I did 560 mixed engine hours and I used 5400 litres "


Dave

Lucky I got new glasses last week I was just able to read the letter you posted....it is very interesting and certainly supports your point...(and also supports my figures of plus 20% at 3500rpm)... well worth posting in full in somemore easily readable format.

Cheers....John

[Outsider1]

Good argument...you are basically saying that 3500rpm comparison is not able to be generalised up and down.........you may well be correct. I am assuming that the 3500 rpm figures are representative across the range. I must have another look at the original data to see what they look like at lower and higher revs. I must admit i find it hard to imagine why a DI motor would use less at trolling speeds than a 4 stroke..?
Nonetheless I was trying to give some dimension to the margin by which a 4 stroke might use less fuel. Certainly it is more complex, no dispute there, but distance over the ground is not useful because of external factors.
What you really need is (as you suggest) to be able to look at a whole of life log and say "I did 560 mixed engine hours and I used 5400 litres "

Yes,

at the end of the day it is how much fuel you have to put into the boat that really matters in a running cost comparison. So we need a measure or calculation that is the best approximation of total fuel used. Not sure on that one, I will have to give it some more thought?.

Cheers

Dave

[Jabba_]

Mindi, don't get the wrong idea that I am trying to justify any motor or what ever... just want to get a more acurite picture

I do like what you are doing..

Cheers

[Outsider1]

Dave

Lucky I got new glasses last week I was just able to read the letter you posted....it is very interesting and certainly supports your point...(and also supports my figures of plus 20% at 3500rpm)... well worth posting in full in somemore easily readable format.

Cheers....John

Hi John,

yes it got shrunk in the upload because the length exceeded 600 pixels. I have rescanned it into 2 parts and re-posted in my original thread and also here. A bit easier to read now!

Cheers

Dave

[marco]

just a small point about the cost of the xd100 . $11.50 is pretty cheap and i would like to know where i could get it for that , $14.21 per litre is what my local guy charges when buying a drum of it .

[Jabba_]

Your dealer is not doing you any favors, My dealer sells me the small bottle for $55 and a drum for $230... But having good friends in the industrie, I can get cheaper then that again...

[Mindi]

Your dealer is not doing you any favors, My dealer sells me the small bottle for $55 and a drum for $230... But having good friends in the industrie, I can get cheaper then that again...


What quantities are they Jabba..? I am not an Etec (or 4 stroke) owner so dont actually buy it

[Mindi]

Hi John,

yes it got shrunk in the upload because the length exceeded 600 pixels. I have rescanned it into 2 parts and re-posted in my original thread and also here. A bit easier to read now!

Cheers

Dave

Dave

I attach the links to my original manufacturers data which show (IMHO) that Andrew is not correct and that a 4 stroke at 1500rpm actually uses less than half a DI. In fact the Suzi uses 0.5 GPH or 11.2 MPG if you prefer that. The DI Etec uses 1.05 GPH and 5.4 MPG.....this is more what you would expect I think.
The comparison is not perfect as the hulls are different and the Suzuki one is probably a bit more easily driven ...but in this case that would be a minor issue.

see

http://www.evinrude.com/NR/rdonlyres/6F8B80FE-D047-4DF9-AFA6-570ADE8F6235/0/PE501.pdf

http://www.suzukimarine.com/boat_builders/boat_tests/smoker_craft_sylvan/sylvan_171_bass_boat/df70/

But I dont think the data supports hair splitting over decimal places....I am reaching the conclusion that a 4 stroke uses about 20% less fuel across the board cf. a comparable DI ... and that seems to make sense to me..? The idea that a DI uses much less at trolling speeds doesnt really ring true...and isnt supported by this example at least.
But it is interesting...plan to ask on a really excellent Etec focussed forum which is well worth a look.

http://forums.etecownersgroup.com/mb/barnaclebill?forum=115573

[Getout]

My 175 outboard cruises at 20-26l/hr but has averaged only 12litres /hr for its 200 engine hrs so far.
I don't do a huge amount of trolling but have spent a bit of time sounding around.
I don't think running costs can be evaluated using cruising speed consumption figures.

[finding_time]

.
I don't think running costs can be evaluated using cruising speed consumption figures.


Spot on Getout!;) 1/4 or less of my hours over summer are cruise speed hrs at 11l per/hr x 2 but most are at 2000 rpm and less than 4l per/hr. Then there's servicing costs. i'm certainly not paying the $500 PLUS per engine bandied around by some.

Plus once the engines are out of waranty self servicing is a real option! Well for the ones that dont require a computer and soft ware that is!;)

[Silverslug]

;D In relation to the ETEC oil , just purched one and the first thing the dealer said was to bring a empty 5 litre bottle to get the filled for $50, that is out of his 200ltr drum i cant see why all Etec dealers cant do the same. I know fuel is getting dearer but if you own a boat of any size and motor and you a worring about the fuel i would suggest you sell it, because no matter 2 stroke or 4stroke you are never going to be happy

[Jabba_]

What quantities are they Jabba..? I am not an Etec (or 4 stroke) owner so dont actually buy it
A bottle is 3.7lt @ $55 and a drum is 19lt at $230... RRP is $80 and $315 accordingly... Never have I seen the oil sold at those prices.....

[marco]

;D In relation to the ETEC oil , just purched one and the first thing the dealer said was to bring a empty 5 litre bottle to get the filled for $50, that is out of his 200ltr drum i cant see why all Etec dealers cant do the same. I know fuel is getting dearer but if you own a boat of any size and motor and you a worring about the fuel i would suggest you sell it, because no matter 2 stroke or 4stroke you are never going to be happy

who is the dealer ?

[marco]

A bottle is 3.7lt @ $55 and a drum is 19lt at $230... RRP is $80 and $315 accordingly... Never have I seen the oil sold at those prices.....

thanks jabba , im on the hunt for a better deal .

your prices work out at

3.7lt is 14.86 / ltr

19 ltr is 12.10/ltr
better but still not 11.50 in the first equation

[Silverslug]

8-) Hi Macro, I live in Hervey Bay and i have it in writting on the invoice i got with the motor $50 and i took a empty 5ltr Valvolene bottle in the next day and it was filled to the 5ltr mark on the measuring window. I would be asking a few questions of your dealer, he not doing you any favours if you purchased a Etec from him. This is the price my dealer charges all his customers .

[Outsider1]

Dave

I attach the links to my original manufacturers data which show (IMHO) that Andrew is not correct and that a 4 stroke at 1500rpm actually uses less than half a DI. In fact the Suzi uses 0.5 GPH or 11.2 MPG if you prefer that. The DI Etec uses 1.05 GPH and 5.4 MPG.....this is more what you would expect I think.
The comparison is not perfect as the hulls are different and the Suzuki one is probably a bit more easily driven ...but in this case that would be a minor issue.

see

http://www.evinrude.com/NR/rdonlyres/6F8B80FE-D047-4DF9-AFA6-570ADE8F6235/0/PE501.pdf

http://www.suzukimarine.com/boat_builders/boat_tests/smoker_craft_sylvan/sylvan_171_bass_boat/df70/

But I dont think the data supports hair splitting over decimal places....I am reaching the conclusion that a 4 stroke uses about 20% less fuel across the board cf. a comparable DI ... and that seems to make sense to me..? The idea that a DI uses much less at trolling speeds doesnt really ring true...and isnt supported by this example at least.
But it is interesting...plan to ask on a really excellent Etec focussed forum which is well worth a look.

http://forums.etecownersgroup.com/mb/barnaclebill?forum=115573

Hi Mindi,

I think it big call to say Andrew Norton does not know his stuff!? He has tested just about every outboard out there, often on a long term basis and he takes indepth full usage figures. He reports them in great detail, and has for years. He also made the comment about the E-Tec 150, whereas you are comparing a Suzy 70 and a E-Tec75!!??

I know nothing about the Suzuki 70 and very little about the E-Tec 75. I agree if you use those two reports then they support your contention, but that is a pretty big bow to draw to then say a DI 2 stroke uses about 20% more fuel than a comparable 4 stroke, based on 2 reports from manufacturers sites on two different boats. If that was true (across the board) do you think they would be selling as many DI 2 strokes as they do!?

I am not looking to defend DI's, let the facts speak for themselves. I suspect on average they do use slightly more than a 4 stroke, but not 20% on the evidence I have seen. It is the trade off for the greater torque and holeshot that you expect from the DI 2 stroke. For example I have seen a thread on another forum which I think you were also involved in where a dealer stated that the E-Tec 75 is actually putting out 82hp. If that is true, then you would definitely expect it to use more fuel than the Suzuki 70, possibly +17% perhaps being 82hp vs 70hp ie +17%, hope you see my point.

As to how you allow for it in the spreadsheet, I have a few thoughts. I will PM you to get a copy and have a look.

Still think this will be a worthwehile exercise if we can get flexibility in the calculations to allow for differing usages etc.

Cheers

Dave

[Outsider1]

I know of a dealer in Sydney that is doing the bulk oil refills deal also at similar prices, but unfortunately don't know of any in SE Qld.

I have picked my XD100 up for $55 per US gallon (3.78 litres) so far.

Cheers

Dave

[Greg P]

Hi Mindi,

I think it big call to say Andrew Norton does not know his stuff!? He has tested just about every outboard out there, often on a long term basis and he takes indepth full usage figures. He reports them in great detail, and has for years.


Dave - you do know that this guy got the arse from F&B for shall we say poorly researched engine tests.


Not saying he is wrong here but dont hold him up as a guru regarding outboard reporting



Cheers

Greg

[Outsider1]

Dave - you do know that this guy got the arse from F&B for shall we say poorly researched engine tests.


Not saying he is wrong here but dont hold him up as a guru regarding outboard reporting



Cheers

Greg

News to me Greg. I have read F & B for years and do not recall every seeing him write anything in there?. He has been the Boating Editor for Saltwater Fishing since inception. Did not think I was holding him up as a guru??

Cheers

Dave

[John_R]

The DI 2 strokes use stratified charge to reduce fuel usage at low revs. The ETEC uses it up to about 1800 rpm then changes to a homogeneous mixture. I think this is how they get better results than a four stroke at low revs.

[Mindi]

thanks jabba , im on the hunt for a better deal .

your prices work out at

3.7lt is 14.86 / ltr

19 ltr is 12.10/ltr
better but still not 11.50 in the first equation

Yeah obviously my $11.50 was pretty hopeful. I got it from someone else's post on here somewhere but now cant find it. Probably not all that significant a difference. Thanks Jabba.

[disorderly]

Hi Mindi,

I think it big call to say Andrew Norton does not know his stuff!? He has tested just about every outboard out there, often on a long term basis and he takes indepth full usage figures. He reports them in great detail, and has for years. He also made the comment about the E-Tec 150, whereas you are comparing a Suzy 70 and a E-Tec75!!??

I know nothing about the Suzuki 70 and very little about the E-Tec 75. I agree if you use those two reports then they support your contention, but that is a pretty big bow to draw to then say a DI 2 stroke uses about 20% more fuel than a comparable 4 stroke, based on 2 reports from manufacturers sites on two different boats. If that was true (across the board) do you think they would be selling as many DI 2 strokes as they do!?


I am not looking to defend DI's, let the facts speak for themselves. I suspect on average they do use slightly more than a 4 stroke, but not 20% on the evidence I have seen. It is the trade off for the greater torque and holeshot that you expect from the DI 2 stroke. For example I have seen a thread on another forum which I think you were also involved in where a dealer stated that the E-Tec 75 is actually putting out 82hp. If that is true, then you would definitely expect it to use more fuel than the Suzuki 70, possibly +17% perhaps being 82hp vs 70hp ie +17%, hope you see my point.

As to how you allow for it in the spreadsheet, I have a few thoughts. I will PM you to get a copy and have a look.

Still think this will be a worthwehile exercise if we can get flexibility in the calculations to allow for differing usages etc.

Cheers

Dave

Good points Dave...it makes Mindi's whole comparison invalid from the start as we are talking about motors of a different HP rating under different conditions on different boats tested by different people with different axes to grind...http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/rolleyes.gif.

Mindi....this is about the most unscientific comparison I could imagine

As for using l/h as a guide...I also remain unconvinced, as the motor will run at every rpm between 0 and WOT over the course of my day's travel....

The only meaningful fuel consumption figures for me are how far I have traveled in the day and how many litres of fuel I used ie km/l http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/smiley.gif.

Scott

[Outsider1]

Mindi kindly sent me a copy of his spreadsheet and I have been having a bit of a look and a think about the running costs comparisons.

It is easy to get bogged down in the complexity of different outboard set ups, performance profiles etc, but they are real and do make these types of comparisons very hard.

I have attached a document that highlights these issues. There is an example of the same motor on 3 different but similar hulls. Fuel consumption for the same motor at the same rpms varies by up to 33%!.

My first thought is can we simplify this back to what Mindi was really trying to compare in the first place. Now I have not discussed it with him, but I assume that one of the things he was trying to compare was the 3 year/300hr service cycle of the E-Tec vs the annual/100hr servicing of the average 4 stroke.

If you assume that fuel consumption is basically the same, then it is a comparison of the cost of 2 stroke oil plus 1 service vs the cost of 3 services. This takes any hull or set up variances out if it.

Adjusting the price of XD100 to $55 for 3.78 litres in the formula and equalising consumption the result shows that the E-Tec would be about $340 cheaper in total @ 50hrs pa for 3 years. If you pump the hours up to 100 pa the difference almost disappears i.e. the cost of the XD100 offsets the savings in service costs.

In the 50 hours pa comparison the E-Tec could use up to 9% more fuel and still be cheaper overall to run.

Cheers

Dave

[STUIE63]

When the figures were done for oil usage what ratio were they calculated at because by Daves PDF the etec/opti would approx 65% of the time be useing less than 100:1 this could be another huge variable in the costings
Stuie

[STUIE63]

mate the variables in this equation would be enough to send Albert Einstein round the twist I'm with Noelm here just get the motor that has a good service agent/dealer in your area
Stuie

[Outsider1]

When the figures were done for oil usage what ratio were they calculated at because by Daves PDF the etec/opti would approx 65% of the time be useing less than 100:1 this could be another huge variable in the costings
Stuie

It worked out at an average of just over 100 to 1, 102.2 to be more precise. This was Mindi's original assumption and appeared quite sound to me.

Yes agree, it is an almost impossible equation with all the variables. We have not really talked about the Optimax for example. It has a displacement of 1.526 litres whereas the Suzy is 1.298 and the E-Tec 1.295 litres. So the Opti has over 17.5% more engine displacement. You would therefore expect it to use more fuel, but on the plus side it should be very torquey, understressed and perform very well. How that translates back to running cots is hard to say though, it really depends on the hull and the set up. On some hulls it may be the only motor you might consider for the particular use.


Cheers

Dave

[disorderly]

It worked out at an average of just over 100 to 1, 102.2 to be more precise. This was Mindi's original assumption and appeared quite sound to me.

Yes agree, it is an almost impossible equation with all the variables. We have not really talked about the Optimax for example. It has a displacement of 1.526 litres whereas the Suzy is 1.298 and the E-Tec 1.295 litres. So the Opti has over 17.5% more engine displacement. You would therefore expect it to use more fuel, but on the plus side it should be very torquey, understressed and perform very well. How that translates back to running cots is hard to say though, it really depends on the hull and the set up. On some hulls it may be the only motor you might consider for the particular use.


Cheers

Dave

So many variables alright...
Since fuel went up and I started driving much slower (I also do quite a bit of trolling)..my XD 100 oil ratio has been around 145 to 1.

I have also noticed in some of the Optimax ads that they claim
figures of 3.28 km/l vs 2.85km/l for the E-tec in the 90 hp...almost 20% right there....I think sometimes such figures are just plucked out of thin air and dont reflect real life situationshttp://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/undecided.gif.

The only way to obtain valid data IMO is to run the same boats side by side with the different brand ,similar sized motors properly setup for those hulls...and even then some motors may perform differently on different hulls but at least you would be comparing apples with apples and get some comparable data.

Scott

[Crocodile]

Fuel is all very well but that is only part of it.
What about rego, insurance, maintenance on the trailer and boat.
The really big cost is depreciation or even worse interest on the loan.
If you have a 75hp motor, total rig cost is at least 30K which will be worth 20K (if you are lucky) after three years so add in ar least 3K per year depreciation.
Don't get too bogged down over a few bucks difference in fuel dollars.