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Author Topic:   E-TEC Fuel Burn Data

jimh posted 06-27-2008 12:57 AM ET (US)
This data comes from Bombardier. It is the average fuel burn for various models of the E-TEC, computed using the ICOMIA five mode duty cycle. The ICOMIA duty cycle is believed to measure the typical outboard engine usage in terms of time run at each of the five speeds.
HP L/HR GAL/HR
40 3.9 1.03
50 3.9 1.03
60 4.3 1.16
75 6.7 1.77
90 7 1.87
115 8.7 2.3
150 12.2 3.2
175 13.8 3.64
200 14.2 3.7
200 16.8 4.4
225 16.8 4.4
250 17.1 4.5
Source: BRP Chart
jimh posted 06-27-2008 01:06 AM ET (US)
The ICOMIA five mode cycle is as follows:
Mode Engine RPM Time
1 Idle 40%
2 40% of max 25%
3 60% of max 15%
4 80% of max 14%
5 max speed 6%
Source: IAME Paper
jimh posted 06-27-2008 01:17 AM ET (US)
I have collected some long term data about my own motor's fuel burn rate. My motor is a classic two-cycle carburetor motor of 225-HP. My data shows over a total of 188.7-hours use I average a fuel flow of 7.36-GPH.
If I compare this to the data for an E-TEC 225-HP, I see it will average about 4.4-GPH. This implies that if I changed my motor to a new E-TEC my fuel consumption would reduce by
7.36 - 4.4 = 2.96-GPH
This is a reduction of 41-percent. The new engine would consume only 59-percent as much fuel as the old engine.
In the last three seasons I have used a total of 1,389-gallons of fuel. If I change to an E-TEC I would only use 1,389 x 0.59 = 819.5-gallons, a savings of 569.5 gallons. At current marina fuel prices of approximately $4.50/gallon, this implies a savings of $2,563 in the next three seasons.
Peter posted 06-27-2008 07:52 AM ET (US)
Jim -- Your cost savings analysis is only accurate if you also run your motor in the same ICOMIA weighted 5 mode duty cycle pattern of the standard. I think it would be a good bet that you don't.
Under the duty cycle, 25 percent of the time is spent at 40 percent of maximum throttle, which would be approximately 2400 RPM. I'll bet that at 2400 RPM your boat is in the on-plane transition and so you are not likely to run at that engine speed for very long, certainly not 25 percent of the time.
boatdryver posted 06-27-2008 08:20 AM ET (US)
What assumptions does the BRP chart make about how much work the motor is doing in each HP range. What size boat, etc? Wouldn't that impact the fuel burn a lot.
JimL
jimh posted 06-27-2008 08:36 AM ET (US)
Another way to look at the effect of lower fuel consumption rate is to just apply it to the price-per-gallon of the fuel. If I get a new engine that only consumes 0.59-times as much fuel, I can say that the new engine reduces the cost of fuel for me by that factor. Thus if fuel sells for $5-per-gallon, the new engine reduces my cost to $5 x 0.59 = $2.95-per-gallon. Of course, I have to invest a considerable amount of money up front to get that discount.
Peter posted 06-27-2008 09:11 AM ET (US)
"What assumptions does the BRP chart make about how much work the motor is doing in each HP range"
The BRP chart is simply a report of total hourly fuel consumption under the ICOMIA duty cycle standard (36-88). The ICOMIA duty cycle standard requires that the engine be operated in the five modes characterized by both engine speed and a fraction of the maximum torque at rated speed. Jim has stated the engine speeds for each of the modes but not the torque fractions. The torque fractions are as follows:
Mode Torque Fraction
1 0.000
2 0.253
3 0.465
4 0.716
5 1.000
The torque fractions ensure that motors are put under a uniform loading otherwise a manufacturer could cheat the duty cycle fuel report by underloading the motor at each engine speed.
"What size boat, etc? Wouldn't that impact the fuel burn a lot"
No. If a motor is propped the same way on two different boats, i.e., the motor reaches the same WOT RPM, and run at the ICOMIA duty cycle engine speeds, the total hourly fuel flow should be substantially the same although the speed of each boat will be different and hence the MPG will be different because MPG is a function of speed. The reality is that there could be a slight difference in actual hourly fuel flow due to differences in the on-plane transition zone.

jimh posted 06-27-2008 09:20 AM ET (US)
Peter--Thank you for the additional information on the ICOMIA specification for torque fraction at each speed. I have not seen that mentioned elsewhere.
Peter posted 06-27-2008 09:23 AM ET (US)
You can read the 36-88 standard by clicking on the 36-88 link here www.icomia.com/library/library.asp?view=Category&LC_ID=14# . This website apparently will not allow a direct link.
jimh posted 06-27-2008 09:26 AM ET (US)
I think the ICOMIA fuel data is valuable, as it gives a standard procedure to collect fuel flow data. If all manufacturers published this data it would allow a reasonable comparison to be easily made among engines. Instead we get boat test reports with many other variables involved, and comparison of engine-to-engine is difficult.
Peter posted 06-27-2008 09:51 AM ET (US)
I agree. Analysis under the standard shed some interesting light on the fuel savings between GEN I and GEN II Verados. See bottom of this additional "conspiracy theory" thread
continuouswave.com/ubb/Forum1/HTML/015389.html
Based on the ICOMIA standard, it seems to me the miniscule fuel savings and operating cost gains are difficult to justify the extensive modifications made to arrive at GEN II.
cooper1958nc posted 06-27-2008 05:40 PM ET (US)
I would bet most of the fuel savings between carb and DI 2-strokes occur at idle or near idle, where the carbed engine spews unbured fuel out the exhaust. At higher RPM and load, the gas dynamics change and the conventional motor is almost as efficient.
I would be very, very surprised if engine management or other tuning changes between Gen I and Gen II result in much more than incremental improvements. Once you are burning, not exhausting, your fuel-air mix, it costs about the same to get the same power.
ratherwhalering posted 06-27-2008 07:07 PM ET (US)
Jim, I like to think of it like the oil companies will pay you $2,563 over the next three years to buy an E-TEC.
Better yet, at your current fuel consumption, the oil companies will pay you about $15.00 an hour while boating if you buy an E-TEC.
fourdfish posted 06-27-2008 11:07 PM ET (US)
Since I have actual experience regarding both the convential and newer DI 2 stroke, totally disagree with cooper1958nc. I have seen an across the board (all speeds) decrease in fuel consumption with the new DI E-TEC. Don't forget actual combustion occurs with both ports closed in the DI E-TEC (at all speeds)
jimh posted 06-28-2008 12:33 AM ET (US)
Since the chart of data which inspired this discussion came from an Australian E-TEC enthusiasts, I make the inference that the data was distributed in Australia as part of the usual marketing data accompanying the E-TEC motors. This raises the question: Is ICOMIA fuel burn data routinely given in other regions as part of the marketing of outboard motors?
If ICOMIA fuel burn data is more often seen in outboard literature outside of the United States, it makes me wonder why we can't see it here. Perhaps manufacturers are still too reliant on flashing visuals in their advertising to North American customers. Maybe they think we won't understand real data.
cooper1958nc posted 06-28-2008 04:48 PM ET (US)
"Don't forget actual combustion occurs with both ports closed in the DI E-TEC (at all speeds)"
What? Is that supposed to be good or bad?
The 2 stroke is a gas dynamic engine. It is *not* possible to understand gas flow at static conditions, any more than it is possible to understand why valve overlap (both intake and exhaust open at the same time) works in a 4 stroke, if you think statically.
If you know the differnce between D1 and D2 engines I would like to hear it.
My remarks are based, as well, on the observation that at cruise speeds, fuel economy is not marketly different between carbed 2 strokes, DI 2 strokes, and 4 strokes, if boat variables are eliminated. Power is power.
fourdfish posted 06-28-2008 08:37 PM ET (US)
Cooper-- My experience and Jim data show you [wrong]. My bank account also shows your wrong and just about any test you read shows DI engines getting better fuel figures. End of story.
jimh posted 06-29-2008 09:47 AM ET (US)
Not to get too far off topic here, but I agree with cooper that the E-TEC engine gives its most remarkable improvement in fuel economy at its lowest speeds where it is using a stratified charge. At higher speeds it changes modes to a homogenous charge. At higher speeds the E-TEC is still more efficient than conventional two-cycle non-direct-injection motors, but the difference is much less.
The most common pattern of use of an outboard has the motor idling or running at low speeds almost 50-percent of the time. As a result, users experience much improved fuel economy because the idle speed performance of the E-TEC is so much better. If the E-TEC were being run at full-throttle 50-percent of the time, I suspect that the user would still see improved fuel economy, but not nearly as much as in the other case.
To get back on topic, the data given here by Bombardier appears to be somewhat unique in the outboard motor business. I have not seen any similar data from other manufacturers. I believe that other manufacturers must have this same data because they collect it as part of their EPA test data for emission certification. If we had this same data from all manufacturers, collected under the same test conditions (which is what the EPA procedure demands), then we would have a simple way to compare fuel consumption among brands and models.
A comparison of fuel consumption based on controlled dynamometer testing would be more useful than the sort of snap shot data often used now to promote an engine, where a manufacturer runs his own test with a certain boat, a certain propeller, a certain body of water, certain weather conditions, certain measurement techniques, and then picks some combination of boat speed and engine speed where his motor does better than the competition and declares himself the winner.
Peter posted 06-29-2008 10:27 AM ET (US)
I've been saying this for a while now, but perhaps the outboard manufacturers could follow what the diesel manufacturers do -- publish power, torque and fuel consumption based on a specified propeller load curves. LINK
fourdfish posted 06-29-2008 03:43 PM ET (US)
I will say it again, As an actual user of both tecnologies, one right after another, I have been getting MUCH better milage. Everyone has a right to their opinion but you would be hard pressed to show me any different. I am talking hundreds of dollars, not chump change!
It is not just trolling which of course only burns one third of a gallon/hr. In fact I have been trolling for the last year or so with my kicker so as to not put so many miles on the big engine.
jimh posted 06-29-2008 04:43 PM ET (US)
fourd'--I am also in total agreement with your observation of improved fuel economy. It is just that I wish that instead of "much better mileage" you could quantify the improvement with some data. This is what I find attractive about Bombardier's release of this ICOMIA fuel burn data: it quantifies the fuel economy that is expected and in a known duty cycle.
Peter--Your point about the ICOMIA duty cycle data at 40-percent throttle is well taken. As a matter of fact, I never run my motor at 40-percent throttle (2,400-RPM) because, as you suggest, that produces a boat speed that is between displacement mode and hydroplane mode, and operation at that speed creates a large wake and very poor fuel economy. In my particular case my operating habits might not fit perfectly with the ICOMIA model.
In regard to operating habits, one beautiful feature of the E-TEC is that it will inform its owner of the operating habits. See my article in the REFERENCE section which details the information an E-TEC will reveal about how it has been used, and also gives a couple of real-world examples from actual E-TEC engine owners. See
E-TEC Engine History Report
http://continuouswave.com/whaler/reference/ETEC_EngineHistoryReport.html
fourdfish posted 06-29-2008 06:11 PM ET (US)
Jim--Unfortunately I do have a fuel flow meter to measure the fuel use. The only way I confirm my observations is by comparing money spent and trip milages. However, The difference is really great and I have been enjoying it. I know that is not scientific but I can't help that now. Now that the price of gas is so high, I am so glad that I purchased the engine when I did! Maybe some day I will purchase and install a flow meter.
cooper1958nc posted 06-29-2008 07:30 PM ET (US)
I agree that DI 2 strokes do better, sometimes very much better, than carbed 2 strokes. The difference is greater at idle for reasons stated above.
My remarks concerned the "D1" vs "D2" debate. I opined that engine management improvements could not account for vast differences in sfc between very similar motors. I thought the D1 and D2's were Verados but I dont' know the details.
The terminology was a little confusing I guess. I agree about DI or computer 2strokes, although, at speed, the difference is less. Anecdotally I operate an Opti and an carbed V4, and there is a big difference in everyday use.
fourdfish posted 06-29-2008 09:45 PM ET (US)
cooper--Did you read the title of this thread? Four Stroke engines were not mentioned! Nor were Optis for yhat matter. Actually Direct Injection (DI) is not really the technology of either of those two engines. Direct Injection meaning: fuel is directly injected into the cylinder without mixing with air. I do not believe the Verado with direct injection has been marketed yet although I do believe they are looking to do that.
an86carrera posted 06-29-2008 10:19 PM ET (US)
My 2008 E-TEC 90-HP at idle burns 0.1-GPH or 35-MPG. At WOT it uses 5.6-MPG at 48 to 52-MPH. There.
Len
jimh posted 06-30-2008 09:39 AM ET (US)
fourd'--In the long run, one's wallet is an accurate fuel flow measuring device, too. As long as you have the data, you're on good scientific principles measuring fuel flow with your wallet, it is just an indirect measurement.
cooper1958nc posted 07-01-2008 11:17 AM ET (US)
Fordfilsh: Well I try to keep things together, but clearly I lack your powers of observation. I try to treat everyone as if they were dinner guests in my home. Your manners need improvement, methinks.
fourdfish posted 07-01-2008 10:46 PM ET (US)
cooper-It is important that you realize that I nor anyone else here guest at your house.
It is also important that we know just exactly what you are posting about in relation to the topic.
Last, other than swearing and name calling, pointing out a problem with someones post is what this board is all about and I personnely am not looking for politeness.

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Author	Topic: E-TEC Fuel Burn Data
jimh	posted 06-27-2008 12:57 AM ET (US) This data comes from Bombardier. It is the average fuel burn for various models of the E-TEC, computed using the ICOMIA five mode duty cycle. The ICOMIA duty cycle is believed to measure the typical outboard engine usage in terms of time run at each of the five speeds. HP L/HR GAL/HR 40 3.9 1.03 50 3.9 1.03 60 4.3 1.16 75 6.7 1.77 90 7 1.87 115 8.7 2.3 150 12.2 3.2 175 13.8 3.64 200 14.2 3.7 200 16.8 4.4 225 16.8 4.4 250 17.1 4.5 Source: BRP Chart
jimh	posted 06-27-2008 01:06 AM ET (US) The ICOMIA five mode cycle is as follows: Mode Engine RPM Time 1 Idle 40% 2 40% of max 25% 3 60% of max 15% 4 80% of max 14% 5 max speed 6% Source: IAME Paper
jimh	posted 06-27-2008 01:17 AM ET (US) I have collected some long term data about my own motor's fuel burn rate. My motor is a classic two-cycle carburetor motor of 225-HP. My data shows over a total of 188.7-hours use I average a fuel flow of 7.36-GPH. If I compare this to the data for an E-TEC 225-HP, I see it will average about 4.4-GPH. This implies that if I changed my motor to a new E-TEC my fuel consumption would reduce by 7.36 - 4.4 = 2.96-GPH This is a reduction of 41-percent. The new engine would consume only 59-percent as much fuel as the old engine. In the last three seasons I have used a total of 1,389-gallons of fuel. If I change to an E-TEC I would only use 1,389 x 0.59 = 819.5-gallons, a savings of 569.5 gallons. At current marina fuel prices of approximately $4.50/gallon, this implies a savings of $2,563 in the next three seasons.
Peter	posted 06-27-2008 07:52 AM ET (US) Jim -- Your cost savings analysis is only accurate if you also run your motor in the same ICOMIA weighted 5 mode duty cycle pattern of the standard. I think it would be a good bet that you don't. Under the duty cycle, 25 percent of the time is spent at 40 percent of maximum throttle, which would be approximately 2400 RPM. I'll bet that at 2400 RPM your boat is in the on-plane transition and so you are not likely to run at that engine speed for very long, certainly not 25 percent of the time.
boatdryver	posted 06-27-2008 08:20 AM ET (US) What assumptions does the BRP chart make about how much work the motor is doing in each HP range. What size boat, etc? Wouldn't that impact the fuel burn a lot. JimL
jimh	posted 06-27-2008 08:36 AM ET (US) Another way to look at the effect of lower fuel consumption rate is to just apply it to the price-per-gallon of the fuel. If I get a new engine that only consumes 0.59-times as much fuel, I can say that the new engine reduces the cost of fuel for me by that factor. Thus if fuel sells for $5-per-gallon, the new engine reduces my cost to $5 x 0.59 = $2.95-per-gallon. Of course, I have to invest a considerable amount of money up front to get that discount.
Peter	posted 06-27-2008 09:11 AM ET (US) "What assumptions does the BRP chart make about how much work the motor is doing in each HP range" The BRP chart is simply a report of total hourly fuel consumption under the ICOMIA duty cycle standard (36-88). The ICOMIA duty cycle standard requires that the engine be operated in the five modes characterized by both engine speed and a fraction of the maximum torque at rated speed. Jim has stated the engine speeds for each of the modes but not the torque fractions. The torque fractions are as follows: Mode Torque Fraction 1 0.000 2 0.253 3 0.465 4 0.716 5 1.000 The torque fractions ensure that motors are put under a uniform loading otherwise a manufacturer could cheat the duty cycle fuel report by underloading the motor at each engine speed. "What size boat, etc? Wouldn't that impact the fuel burn a lot" No. If a motor is propped the same way on two different boats, i.e., the motor reaches the same WOT RPM, and run at the ICOMIA duty cycle engine speeds, the total hourly fuel flow should be substantially the same although the speed of each boat will be different and hence the MPG will be different because MPG is a function of speed. The reality is that there could be a slight difference in actual hourly fuel flow due to differences in the on-plane transition zone.
jimh	posted 06-27-2008 09:20 AM ET (US) Peter--Thank you for the additional information on the ICOMIA specification for torque fraction at each speed. I have not seen that mentioned elsewhere.
Peter	posted 06-27-2008 09:23 AM ET (US) You can read the 36-88 standard by clicking on the 36-88 link here www.icomia.com/library/library.asp?view=Category&LC_ID=14# . This website apparently will not allow a direct link.
jimh	posted 06-27-2008 09:26 AM ET (US) I think the ICOMIA fuel data is valuable, as it gives a standard procedure to collect fuel flow data. If all manufacturers published this data it would allow a reasonable comparison to be easily made among engines. Instead we get boat test reports with many other variables involved, and comparison of engine-to-engine is difficult.
Peter	posted 06-27-2008 09:51 AM ET (US) I agree. Analysis under the standard shed some interesting light on the fuel savings between GEN I and GEN II Verados. See bottom of this additional "conspiracy theory" thread continuouswave.com/ubb/Forum1/HTML/015389.html Based on the ICOMIA standard, it seems to me the miniscule fuel savings and operating cost gains are difficult to justify the extensive modifications made to arrive at GEN II.
cooper1958nc	posted 06-27-2008 05:40 PM ET (US) I would bet most of the fuel savings between carb and DI 2-strokes occur at idle or near idle, where the carbed engine spews unbured fuel out the exhaust. At higher RPM and load, the gas dynamics change and the conventional motor is almost as efficient. I would be very, very surprised if engine management or other tuning changes between Gen I and Gen II result in much more than incremental improvements. Once you are burning, not exhausting, your fuel-air mix, it costs about the same to get the same power.
ratherwhalering	posted 06-27-2008 07:07 PM ET (US) Jim, I like to think of it like the oil companies will pay you $2,563 over the next three years to buy an E-TEC. Better yet, at your current fuel consumption, the oil companies will pay you about $15.00 an hour while boating if you buy an E-TEC.
fourdfish	posted 06-27-2008 11:07 PM ET (US) Since I have actual experience regarding both the convential and newer DI 2 stroke, totally disagree with cooper1958nc. I have seen an across the board (all speeds) decrease in fuel consumption with the new DI E-TEC. Don't forget actual combustion occurs with both ports closed in the DI E-TEC (at all speeds)
jimh	posted 06-28-2008 12:33 AM ET (US) Since the chart of data which inspired this discussion came from an Australian E-TEC enthusiasts, I make the inference that the data was distributed in Australia as part of the usual marketing data accompanying the E-TEC motors. This raises the question: Is ICOMIA fuel burn data routinely given in other regions as part of the marketing of outboard motors? If ICOMIA fuel burn data is more often seen in outboard literature outside of the United States, it makes me wonder why we can't see it here. Perhaps manufacturers are still too reliant on flashing visuals in their advertising to North American customers. Maybe they think we won't understand real data.
cooper1958nc	posted 06-28-2008 04:48 PM ET (US) "Don't forget actual combustion occurs with both ports closed in the DI E-TEC (at all speeds)" What? Is that supposed to be good or bad? The 2 stroke is a gas dynamic engine. It is not possible to understand gas flow at static conditions, any more than it is possible to understand why valve overlap (both intake and exhaust open at the same time) works in a 4 stroke, if you think statically. If you know the differnce between D1 and D2 engines I would like to hear it. My remarks are based, as well, on the observation that at cruise speeds, fuel economy is not marketly different between carbed 2 strokes, DI 2 strokes, and 4 strokes, if boat variables are eliminated. Power is power.
fourdfish	posted 06-28-2008 08:37 PM ET (US) Cooper-- My experience and Jim data show you [wrong]. My bank account also shows your wrong and just about any test you read shows DI engines getting better fuel figures. End of story.
jimh	posted 06-29-2008 09:47 AM ET (US) Not to get too far off topic here, but I agree with cooper that the E-TEC engine gives its most remarkable improvement in fuel economy at its lowest speeds where it is using a stratified charge. At higher speeds it changes modes to a homogenous charge. At higher speeds the E-TEC is still more efficient than conventional two-cycle non-direct-injection motors, but the difference is much less. The most common pattern of use of an outboard has the motor idling or running at low speeds almost 50-percent of the time. As a result, users experience much improved fuel economy because the idle speed performance of the E-TEC is so much better. If the E-TEC were being run at full-throttle 50-percent of the time, I suspect that the user would still see improved fuel economy, but not nearly as much as in the other case. To get back on topic, the data given here by Bombardier appears to be somewhat unique in the outboard motor business. I have not seen any similar data from other manufacturers. I believe that other manufacturers must have this same data because they collect it as part of their EPA test data for emission certification. If we had this same data from all manufacturers, collected under the same test conditions (which is what the EPA procedure demands), then we would have a simple way to compare fuel consumption among brands and models. A comparison of fuel consumption based on controlled dynamometer testing would be more useful than the sort of snap shot data often used now to promote an engine, where a manufacturer runs his own test with a certain boat, a certain propeller, a certain body of water, certain weather conditions, certain measurement techniques, and then picks some combination of boat speed and engine speed where his motor does better than the competition and declares himself the winner.
Peter	posted 06-29-2008 10:27 AM ET (US) I've been saying this for a while now, but perhaps the outboard manufacturers could follow what the diesel manufacturers do -- publish power, torque and fuel consumption based on a specified propeller load curves. LINK
fourdfish	posted 06-29-2008 03:43 PM ET (US) I will say it again, As an actual user of both tecnologies, one right after another, I have been getting MUCH better milage. Everyone has a right to their opinion but you would be hard pressed to show me any different. I am talking hundreds of dollars, not chump change! It is not just trolling which of course only burns one third of a gallon/hr. In fact I have been trolling for the last year or so with my kicker so as to not put so many miles on the big engine.
jimh	posted 06-29-2008 04:43 PM ET (US) fourd'--I am also in total agreement with your observation of improved fuel economy. It is just that I wish that instead of "much better mileage" you could quantify the improvement with some data. This is what I find attractive about Bombardier's release of this ICOMIA fuel burn data: it quantifies the fuel economy that is expected and in a known duty cycle. Peter--Your point about the ICOMIA duty cycle data at 40-percent throttle is well taken. As a matter of fact, I never run my motor at 40-percent throttle (2,400-RPM) because, as you suggest, that produces a boat speed that is between displacement mode and hydroplane mode, and operation at that speed creates a large wake and very poor fuel economy. In my particular case my operating habits might not fit perfectly with the ICOMIA model. In regard to operating habits, one beautiful feature of the E-TEC is that it will inform its owner of the operating habits. See my article in the REFERENCE section which details the information an E-TEC will reveal about how it has been used, and also gives a couple of real-world examples from actual E-TEC engine owners. See E-TEC Engine History Report http://continuouswave.com/whaler/reference/ETEC_EngineHistoryReport.html
fourdfish	posted 06-29-2008 06:11 PM ET (US) Jim--Unfortunately I do have a fuel flow meter to measure the fuel use. The only way I confirm my observations is by comparing money spent and trip milages. However, The difference is really great and I have been enjoying it. I know that is not scientific but I can't help that now. Now that the price of gas is so high, I am so glad that I purchased the engine when I did! Maybe some day I will purchase and install a flow meter.
cooper1958nc	posted 06-29-2008 07:30 PM ET (US) I agree that DI 2 strokes do better, sometimes very much better, than carbed 2 strokes. The difference is greater at idle for reasons stated above. My remarks concerned the "D1" vs "D2" debate. I opined that engine management improvements could not account for vast differences in sfc between very similar motors. I thought the D1 and D2's were Verados but I dont' know the details. The terminology was a little confusing I guess. I agree about DI or computer 2strokes, although, at speed, the difference is less. Anecdotally I operate an Opti and an carbed V4, and there is a big difference in everyday use.
fourdfish	posted 06-29-2008 09:45 PM ET (US) cooper--Did you read the title of this thread? Four Stroke engines were not mentioned! Nor were Optis for yhat matter. Actually Direct Injection (DI) is not really the technology of either of those two engines. Direct Injection meaning: fuel is directly injected into the cylinder without mixing with air. I do not believe the Verado with direct injection has been marketed yet although I do believe they are looking to do that.
an86carrera	posted 06-29-2008 10:19 PM ET (US) My 2008 E-TEC 90-HP at idle burns 0.1-GPH or 35-MPG. At WOT it uses 5.6-MPG at 48 to 52-MPH. There. Len
jimh	posted 06-30-2008 09:39 AM ET (US) fourd'--In the long run, one's wallet is an accurate fuel flow measuring device, too. As long as you have the data, you're on good scientific principles measuring fuel flow with your wallet, it is just an indirect measurement.
cooper1958nc	posted 07-01-2008 11:17 AM ET (US) Fordfilsh: Well I try to keep things together, but clearly I lack your powers of observation. I try to treat everyone as if they were dinner guests in my home. Your manners need improvement, methinks.
fourdfish	posted 07-01-2008 10:46 PM ET (US) cooper-It is important that you realize that I nor anyone else here guest at your house. It is also important that we know just exactly what you are posting about in relation to the topic. Last, other than swearing and name calling, pointing out a problem with someones post is what this board is all about and I personnely am not looking for politeness.