E-TEC 150 v. Honda BF150: Fuel Economy - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  E-TEC 150 v. Honda BF150: Fuel Economy

search | FAQ | profile | register | author help

Author Topic:   E-TEC 150 v. Honda BF150: Fuel Economy

theollie posted 02-07-2008 04:01 PM ET (US)
I'm helping my dad research the gas mileage for the Evinrude E-TEC 150 and Honda BF150. Any information on new models would be greatly appreciated. Thank you.
fourdfish posted 02-07-2008 05:18 PM ET (US)
I think you might find some differences one way or the other but will they really be significant enough to use that as
factor for purchase. Many other factors might come in to play.
Example, weight, service, price etc
Perry posted 02-07-2008 06:11 PM ET (US)
What kind od boat will the motor be mounted on?
theollie posted 02-07-2008 07:02 PM ET (US)
it's an 18 1/2 feet welded aluminum boat made by a custom boat manufacturer here in south louisiana. thanks for the replies.
Perry posted 02-07-2008 09:50 PM ET (US)
According to test reports like the "150 HP Shoot-Out" by Trailer Boats magazine, the BF150 will get beter fuel economy than the 150 ETEC. I get over 6 MPG cruise with the same Honda on my 19 foot Whaler.
But like fourdfish said, there are other factors that may influence the decision to repower a boat.
jimh posted 02-07-2008 10:26 PM ET (US)
The naturally aspirated four-cycle outboard is probably the best for fuel economy, and among those the Honda is the leader. If fuel economy is the metric, I think a BF150 will probably beat an E-TEC 150. The real question is by how much.
About the best you can do here is to get some anecdotal reports from owners. I don't recall any really scientific head-to-head tests for fuel economy. There have been some magazine tests published which might have some data. Also, most manufacturers now have quite a listing of boat tests with their motors, so if you can find a comparable boat which has been tested with both the E-TEC 150 and the Honda BF150 you may be able to get some data.
towboater posted 02-08-2008 01:16 PM ET (US)
Hypothetical problem.
Let's say the BF 150 cruises 35 mph using 5 gph, and
the Etec 150 (being lighter and given more torque) will cruise 40 mph using 6 gph on the same boat.
Thus, the BF 150 has about 15% better mileage on paper.
A waypoint is 105 miles away.
The BF 150 will take 3 hours and use 15 gals.
The Etec 150 will take 2.65 hours and use 15.9 gals.
Thus, the true difference in fuel mileage is more like 7%.
Thanks for correcting me if I am wrong.
mk

Tom W Clark posted 02-08-2008 01:23 PM ET (US)
Mike,
35 MPH divided by 5 GPH is 7 MPG.
40 MPH divided by 6 GPH is 6.67 MPG
In this example the Honda gets 5 percent better fuel mileage, not 15 percent.
Tohsgib posted 02-08-2008 02:01 PM ET (US)
Towboater I hope you are not the one who calculates my tow bill ;)
AZdave posted 02-08-2008 04:02 PM ET (US)
I get a 5% difference using towboater's numbers. I think he may have rounded off the time for the Etec. His method is exactly correct though. You can get in trouble with rate problems. I think Jimh had a carefully thought out thread along those lines. Well, off to the endodontist. Hope you enjoy your afternoon more than I will. Dave
towboater posted 02-08-2008 04:27 PM ET (US)
NOw wait a minute there Thomas.
It is a fairly primative question. A primitive answer.
Ive caught myself getting all worked up with new engine fuel efficiency when (thanks to you and jim) I realized real time fuel consumption "DEPENDS" on many other factors (long ago).
Jim has a great reply, I should have left it that. hehe.
Lousy weather. Boring Bookwork. soo. I think my math is correct. Tos, I will make sure my hourly rate for your tow bill is appropriate ;-)
wheres my error?
The BF 150 example burns 5 gals per hour at 35 mph.
105 miles / 35 mph = 3 hours
3 hrs x 5 gph = 15 gals to travel 105 miles.
Etec burns 6 gph and runs 40 mph.
105/40 = 2.652 hours x 6 gph = 15.75 gals to travel 105 miles.
Honda gets 5% better mileage on paper. opps. OK. Thanks on that. Is .75 more gals to travel 105 miles also 5%?
Now that I look at it, probably pretty close. The biggest difference is getting there 20 mins sooner.
no comments ness...
I feel enough like a idiot. Back to work.
mk

fourdfish posted 02-09-2008 06:52 PM ET (US)
Actually 4.76% to be exact!
fourdfish posted 02-09-2008 10:22 PM ET (US)
BTW-- 5% or less is not considered significant in any test.
+ or - 5% error is the standard. Several tests will show that much difference.
Perry posted 02-09-2008 11:04 PM ET (US)

quote:
Actually 4.76% to be exact!
Exact in towboater's hypothetcal example.
jimh posted 02-10-2008 09:08 AM ET (US)
I believe that the reference made earlier to my article on fuel economy calculations was to
Average Fuel Mileage: Proper Weighting Factors
http://continuouswave.com/whaler/reference/averageMPG.html
The proposed comparison is this:
BF150 = 35-MPH at 5-GPH
E-TEC 150 = 40-MPH at 6-GPH
over a course of 105-miles distance.
Fuel mileage is in terms of gallons per mile. We have to compute the gallons being consumed for each motor. First we find the time for each to complete the course:
BF-150 at 35-MPH takes 105/35 or 3.0-hours
E-TEC at 40-MPH takes 105/40 or 2.625-hours
Now we find the fuel burned:
BF-150 at 5-GPH for 3.0-hours burns 15-gallons
E-TEC at 6-GPH for 2.625-hours burns 15.75-gallons
The distance was the same for both, 105 miles, so the fuel mileage is
BF-150 goes 105 miles with 15 gallons or 7-MPG
E-TEC goes 105 miles with 15.75 gallons or 6.66-MPG
In this hypothetical comparison of the two motors operating at difference boat speeds, the hypothetical BF-150 has a hypothetical advantage of 5-percent better fuel mileage than the hypothetical E-TEC.
This analysis is not really the focus of my earlier article. In my earlier article I described a method in which the aggregate fuel economy of a motor and boat combination could be computed based on using several different speeds. The best method for weighting the individual speed results is to weight their influence into the averaged total fuel mileage by the amount of fuel being burned at each speed, not by the time at each speed or by the distance covered at each speed.
fourdfish posted 02-10-2008 09:46 AM ET (US)
Your right Perry, that was towboats data!
However, Jims result is also 5% and does take in some other factors. I still say that running the test many more times with as many controls on all the different factors will give different results and less than + or - 5% is not considered scientifically significant.
Perry posted 02-10-2008 01:51 PM ET (US)
I agree that speed influences fuel burn and different motors get better fuel economy at different speeds. The best scenario is to have your motor get its best fuel economy at the speed which is the most comfortable to cruise in the conditions you normally boat in.
Hypothetical fuel consumption is a good way to make a point about fuel burn at different speeds but not in comparing one brand of motor to another.
jimh posted 02-10-2008 02:17 PM ET (US)
Although many people toss out figures about their boat's fuel mileage, in many cases I have to wonder how they derived those numbers. Some of these figures are just drawn from the roughest of estimates, based on a seat-of-the-pants' estimate for distance and fuel use based on refills of a tank to various levels.
On the other hand, I have a fuel flow transducer in my fuel line and a GPS which monitors speed. The two contribute data to a computer which calculates fuel mileage. I have found that depending on the weather, the boat's load, the wind, and the sea state, that my boat's fuel economy varies from 1.7-MPG to 2.4-MPG, all at the same speed! This is a variation of over 40-percent, and again, this is at the same speed, with the same boat, with the same motor, the same measurement instrumentation, and the same people running the test.
So when someone tries to make a decision on a motor based on differences in fuel economy which are as small as 5-percent and based on tests which have been conducted by different people, at different times, on different boats, in different conditions, on different waters--well, you get the idea--5-percent is not exactly enough difference to throw out one candidate over another.

Perry posted 02-10-2008 07:33 PM ET (US)
jimh, I also have a Navman 3100 fuel hooked up to my GPS which computes my fuel consumption but my results vary only slightly depending on load, wind, etc.
I don't understand why 5% is being used when comparing two different motors? Why 5%?
jimh posted 02-10-2008 08:24 PM ET (US)
Perry--You have a fine four-cycle motor made by Honda. I think that is an influence on your fuel economy and how consistently it is measured. My old two-cycle motor is a gas guzzler at certain throttle settings and loads, and the Navman 3100 shows me just how bad it can get sometimes.
I'd be totally comfortable with your data on fuel consumption, inasmuch as you are actually monitoring it. A lot of other reports of fuel economy tend to be much less scientifically derived.
cooper1958nc posted 02-11-2008 07:25 PM ET (US)
There is a lot of discussion here about the fuel economy of various outboards.
Standard four stroke aero, auto, and marine engines are extremely similar in their specific fuel consumption. They run at best sfc under these conditions:
1. Lowest reasonable RPM for the power produced, to reduce engine friction.
2. Manifold pressures (throttle settings) of about 50% of full throttle.
3. Leanest possible mixture, near the onset of lean misfire.
4. Most advanced timing, near the threshold of detonation.
The gearing and propping control 1 and 2; the engine computer controls 3 and 4. There are few significant differences among engines if these factors are controlled.
Noncomputer carburated two strokes have much higher sfc, especially at slow speeds. Computer and injected two strokes are similar to 4 strokes in sfc.
My point is there is probably no difference among modern outboards that is not related to propping, gearing, or boat hull differences.


Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: E-TEC 150 v. Honda BF150: Fuel Economy
theollie	posted 02-07-2008 04:01 PM ET (US) I'm helping my dad research the gas mileage for the Evinrude E-TEC 150 and Honda BF150. Any information on new models would be greatly appreciated. Thank you.
fourdfish	posted 02-07-2008 05:18 PM ET (US) I think you might find some differences one way or the other but will they really be significant enough to use that as factor for purchase. Many other factors might come in to play. Example, weight, service, price etc
Perry	posted 02-07-2008 06:11 PM ET (US) What kind od boat will the motor be mounted on?
theollie	posted 02-07-2008 07:02 PM ET (US) it's an 18 1/2 feet welded aluminum boat made by a custom boat manufacturer here in south louisiana. thanks for the replies.
Perry	posted 02-07-2008 09:50 PM ET (US) According to test reports like the "150 HP Shoot-Out" by Trailer Boats magazine, the BF150 will get beter fuel economy than the 150 ETEC. I get over 6 MPG cruise with the same Honda on my 19 foot Whaler. But like fourdfish said, there are other factors that may influence the decision to repower a boat.
jimh	posted 02-07-2008 10:26 PM ET (US) The naturally aspirated four-cycle outboard is probably the best for fuel economy, and among those the Honda is the leader. If fuel economy is the metric, I think a BF150 will probably beat an E-TEC 150. The real question is by how much. About the best you can do here is to get some anecdotal reports from owners. I don't recall any really scientific head-to-head tests for fuel economy. There have been some magazine tests published which might have some data. Also, most manufacturers now have quite a listing of boat tests with their motors, so if you can find a comparable boat which has been tested with both the E-TEC 150 and the Honda BF150 you may be able to get some data.
towboater	posted 02-08-2008 01:16 PM ET (US) Hypothetical problem. Let's say the BF 150 cruises 35 mph using 5 gph, and the Etec 150 (being lighter and given more torque) will cruise 40 mph using 6 gph on the same boat. Thus, the BF 150 has about 15% better mileage on paper. A waypoint is 105 miles away. The BF 150 will take 3 hours and use 15 gals. The Etec 150 will take 2.65 hours and use 15.9 gals. Thus, the true difference in fuel mileage is more like 7%. Thanks for correcting me if I am wrong. mk
Tom W Clark	posted 02-08-2008 01:23 PM ET (US) Mike, 35 MPH divided by 5 GPH is 7 MPG. 40 MPH divided by 6 GPH is 6.67 MPG In this example the Honda gets 5 percent better fuel mileage, not 15 percent.
Tohsgib	posted 02-08-2008 02:01 PM ET (US) Towboater I hope you are not the one who calculates my tow bill ;)
AZdave	posted 02-08-2008 04:02 PM ET (US) I get a 5% difference using towboater's numbers. I think he may have rounded off the time for the Etec. His method is exactly correct though. You can get in trouble with rate problems. I think Jimh had a carefully thought out thread along those lines. Well, off to the endodontist. Hope you enjoy your afternoon more than I will. Dave
towboater	posted 02-08-2008 04:27 PM ET (US) NOw wait a minute there Thomas. It is a fairly primative question. A primitive answer. Ive caught myself getting all worked up with new engine fuel efficiency when (thanks to you and jim) I realized real time fuel consumption "DEPENDS" on many other factors (long ago). Jim has a great reply, I should have left it that. hehe. Lousy weather. Boring Bookwork. soo. I think my math is correct. Tos, I will make sure my hourly rate for your tow bill is appropriate ;-) wheres my error? The BF 150 example burns 5 gals per hour at 35 mph. 105 miles / 35 mph = 3 hours 3 hrs x 5 gph = 15 gals to travel 105 miles. Etec burns 6 gph and runs 40 mph. 105/40 = 2.652 hours x 6 gph = 15.75 gals to travel 105 miles. Honda gets 5% better mileage on paper. opps. OK. Thanks on that. Is .75 more gals to travel 105 miles also 5%? Now that I look at it, probably pretty close. The biggest difference is getting there 20 mins sooner. no comments ness... I feel enough like a idiot. Back to work. mk
fourdfish	posted 02-09-2008 06:52 PM ET (US) Actually 4.76% to be exact!
fourdfish	posted 02-09-2008 10:22 PM ET (US) BTW-- 5% or less is not considered significant in any test. + or - 5% error is the standard. Several tests will show that much difference.
Perry	posted 02-09-2008 11:04 PM ET (US) quote: Actually 4.76% to be exact! Exact in towboater's hypothetcal example.
jimh	posted 02-10-2008 09:08 AM ET (US) I believe that the reference made earlier to my article on fuel economy calculations was to Average Fuel Mileage: Proper Weighting Factors http://continuouswave.com/whaler/reference/averageMPG.html The proposed comparison is this: BF150 = 35-MPH at 5-GPH E-TEC 150 = 40-MPH at 6-GPH over a course of 105-miles distance. Fuel mileage is in terms of gallons per mile. We have to compute the gallons being consumed for each motor. First we find the time for each to complete the course: BF-150 at 35-MPH takes 105/35 or 3.0-hours E-TEC at 40-MPH takes 105/40 or 2.625-hours Now we find the fuel burned: BF-150 at 5-GPH for 3.0-hours burns 15-gallons E-TEC at 6-GPH for 2.625-hours burns 15.75-gallons The distance was the same for both, 105 miles, so the fuel mileage is BF-150 goes 105 miles with 15 gallons or 7-MPG E-TEC goes 105 miles with 15.75 gallons or 6.66-MPG In this hypothetical comparison of the two motors operating at difference boat speeds, the hypothetical BF-150 has a hypothetical advantage of 5-percent better fuel mileage than the hypothetical E-TEC. This analysis is not really the focus of my earlier article. In my earlier article I described a method in which the aggregate fuel economy of a motor and boat combination could be computed based on using several different speeds. The best method for weighting the individual speed results is to weight their influence into the averaged total fuel mileage by the amount of fuel being burned at each speed, not by the time at each speed or by the distance covered at each speed.
fourdfish	posted 02-10-2008 09:46 AM ET (US) Your right Perry, that was towboats data! However, Jims result is also 5% and does take in some other factors. I still say that running the test many more times with as many controls on all the different factors will give different results and less than + or - 5% is not considered scientifically significant.
Perry	posted 02-10-2008 01:51 PM ET (US) I agree that speed influences fuel burn and different motors get better fuel economy at different speeds. The best scenario is to have your motor get its best fuel economy at the speed which is the most comfortable to cruise in the conditions you normally boat in. Hypothetical fuel consumption is a good way to make a point about fuel burn at different speeds but not in comparing one brand of motor to another.
jimh	posted 02-10-2008 02:17 PM ET (US) Although many people toss out figures about their boat's fuel mileage, in many cases I have to wonder how they derived those numbers. Some of these figures are just drawn from the roughest of estimates, based on a seat-of-the-pants' estimate for distance and fuel use based on refills of a tank to various levels. On the other hand, I have a fuel flow transducer in my fuel line and a GPS which monitors speed. The two contribute data to a computer which calculates fuel mileage. I have found that depending on the weather, the boat's load, the wind, and the sea state, that my boat's fuel economy varies from 1.7-MPG to 2.4-MPG, all at the same speed! This is a variation of over 40-percent, and again, this is at the same speed, with the same boat, with the same motor, the same measurement instrumentation, and the same people running the test. So when someone tries to make a decision on a motor based on differences in fuel economy which are as small as 5-percent and based on tests which have been conducted by different people, at different times, on different boats, in different conditions, on different waters--well, you get the idea--5-percent is not exactly enough difference to throw out one candidate over another.
Perry	posted 02-10-2008 07:33 PM ET (US) jimh, I also have a Navman 3100 fuel hooked up to my GPS which computes my fuel consumption but my results vary only slightly depending on load, wind, etc. I don't understand why 5% is being used when comparing two different motors? Why 5%?
jimh	posted 02-10-2008 08:24 PM ET (US) Perry--You have a fine four-cycle motor made by Honda. I think that is an influence on your fuel economy and how consistently it is measured. My old two-cycle motor is a gas guzzler at certain throttle settings and loads, and the Navman 3100 shows me just how bad it can get sometimes. I'd be totally comfortable with your data on fuel consumption, inasmuch as you are actually monitoring it. A lot of other reports of fuel economy tend to be much less scientifically derived.
cooper1958nc	posted 02-11-2008 07:25 PM ET (US) There is a lot of discussion here about the fuel economy of various outboards. Standard four stroke aero, auto, and marine engines are extremely similar in their specific fuel consumption. They run at best sfc under these conditions: 1. Lowest reasonable RPM for the power produced, to reduce engine friction. 2. Manifold pressures (throttle settings) of about 50% of full throttle. 3. Leanest possible mixture, near the onset of lean misfire. 4. Most advanced timing, near the threshold of detonation. The gearing and propping control 1 and 2; the engine computer controls 3 and 4. There are few significant differences among engines if these factors are controlled. Noncomputer carburated two strokes have much higher sfc, especially at slow speeds. Computer and injected two strokes are similar to 4 strokes in sfc. My point is there is probably no difference among modern outboards that is not related to propping, gearing, or boat hull differences.