posted 10-14-2010 10:41 PM ET (US)        

I operate an ultra-low emission two-cycle engine. The exhaust emission gases of my engine are certified by the United States Environmental Protection Agency, the California Air Resources Board, and the European Union to be of the lowest emission level or cleanest possible emission level for an internal combustion engine. My engine produces no waste associated with oil changes such as used oil filters, dirty rags, oily containers, and so on. As far as I can tell, and to the best of my knowledge, the environmental impact of operating my engine is lower than any other internal combustion engine. I actually feel quite proud to be operating such a clean engine. I feel that operating a clean engine is my proper role in my own individual stewardship of the environment. For example, this past season I operated my boat in the waters of the Isle Royale National Park, a wilderness preservation in Lake Superior. While there are no regulations limiting the type of outboard motor that can be used there, I felt that visiting there in my boat when powered by an Ultra-low emission outboard motor was in harmony with the goal of the park in preserving Isle Royale in an undisturbed and natural state.

posted 10-14-2010 11:23 PM ET (US)            

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My engine produces no waste associated with oil changes such as used oil filters, dirty rags, oily containers, and so on

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Really? When I tour the isles of the marine supply stores, I see all sorts of oily containers with 2-stroke engine oil in them. After I am through using the oil, I always seem to have an oily container to dispose of. And having owned 2 stroke engines, when transferring that oil to another container you will invariably come upon a point when some of the oil does not make it into the new container, and will require a rag to tidy things up. Yes, technically, this is not an "oil change", but the result is the same.

posted 10-15-2010 12:28 AM ET (US)            

You think that your boat that gets 3mpg is not disturbing a natural place where you are filtering your exhaust through the water? That your motor which burns more fuel in one hour or 25 milesor so in which my hybrid car burns in 500 miles or 2 weeks is a postive impact on the environment just because it is ultra-low emissions and you reuse your oil containers....really? Explain to me how anything that gets 3mpg is ultra-low in emissions please.

posted 10-15-2010 12:51 AM ET (US)            

So which is it? Why don't we split this thread?

posted 10-15-2010 09:05 AM ET (US)            

Another side of environmental impact is the wear and increased emissions of a 4-stroke motor as it ages.

Emission testing is done on new motors and they are required to pass the testing for up to 350 hours of operation at ICOMIA duty cycles.

As the 4-stroke wears over time, the oil control rings allow more engine oil to enter the combustion chamber as do the valve guides and seals. This increases hydrocarbons by a large amount.

posted 10-15-2010 09:08 AM ET (US)            

Yes, I agree that it is hard to make a case for any use of a recreational boat powered by any internal combustion engine as having no cost to the environment. However, as boaters, we should not be putting forth that argument. We should leave that kind of nuclear solution to the environmental extremists who would want to outlaw recreational boating.

posted 10-15-2010 10:48 AM ET (US)            

The most recent information I've read puts the E-Tec engine at the top of the least polluting engines list. When containers are reused as many of us buying high cost oil from bulk sellers do it further limits pollution. Disposal of oily plastic containers is avoided. This is the best way to handle our two stroke oil.

I now have a four stroke Verado and intend to change the engine oil and filter myself when the time comes. I don't believe the engine oil I'll use is available from a bulk supplier. So, I'll save the empty plastic oil containers for disposing of the old oil at the next change. I'll carefully drain the oil filter for a few days and the oil drained will go into a used oil container. The next time I buy oil the old containers and oil will go back to the seller so the oil can be recycled. I expect there will be some minimum spillage and that I'll have to dispose of a couple of oily paper towels after each oil change.

There is an argument that can be made that it may be kinder to the environment to recycle old oil than it is to burn it. I don't know which is less harmful but I suspect recycling would win. As recycling uses energy in the process it is not completely free of pollution.

I suspect that the latest iterations of DFI two stroke and EFI four stroke engines over a life of several hundred hours will contaminate the environment about equally per horsepower. The next iteration of four stroke engines will likely be DFI rather than EFI. If you look at automotive engines as precursors you'll observe that DFI four strokes are producing much more horsepower per cubic inch of displacement then EFI engines while producing less environmental pollution.

DFI four stroke outboard engines will be able to produce more horsepower with less displacement than current four strokes. This will allow four cylinder engines to produce power previously available only from six cylinder engines, etc. This will allow less weight on transoms and even less fuel to be burned. The next few years of outboard engine development should be very interesting.

posted 10-15-2010 01:48 PM ET (US)            

Despite the benefits of DFI, I don't think we are going to be witnessing 4-stroke DFI outboards anytime soon for the simple reason that the DFI technology adds even greater cost, compexity, more moving parts and more weight. The small reduction (not more than 10 percent) in displacement that might be achievable to deliver the same HP will not offset the additional weight of the DFI system. Displacement cannot be reduced significantly without impacting the ability to run in statified charging mode which is where the greatest fuel economy gains are found.

posted 10-21-2010 02:57 AM ET (US)            

We did a 50 mile run from Bull Frog Marina down to Rainbow Bridge, the largest natural arch in the world. I think its about a 40 mile run. Add the side canyons and some in and outs and it was about 70 miles one way. Thank goodness for a 90 gallon tank on my 20 Outrage. We were loaded with 8 people.

My Yamaha is a non star, oil burning pig in that mixs oil in a variable fashion from 25-50 to 1 ratio. I refilled that night with Yamalube and looked where it had all gone and frankly its not a good thing. I love the 20 stroke kick and simplicity of the EFI system, no emissions of the Yamaha ox66, but I am not doing anyone any favors. Its a pretty dirty machine.

In an enclosed upland lake, like Lake Powell, I wish I were running a cleaner outboard. I would love an E-tec or the new larger displacment Yamaha that just came out.

posted 10-21-2010 01:23 PM ET (US)            

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And what about the environmental cost of operating a older, v-8 powered truck to haul your boat around?

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posted 11-01-2010 10:07 AM ET (US)         

Ha! Come on... you're going to have to justify that a little more if you are serious about that. If we avoided buying new for environmental reasons, then we'd still be driving even less efficient engines. Whatever environmental burden is associated with that stays with the motor when it changes hands... after all, the used motor still uses that technology, right?

Jim- what is the fate of burned two cycle oil? Water quality? Air? What percent is combusted? The two stroke must be worse for at least the local environment, since the four stroke oil circulates in a relatively closed system.

Another question- assuming the two oils (4 and 2) are equal in their environmental impact, per operating hour how do similar HP motors compare in oil usage?

posted 11-01-2010 11:10 AM ET (US)            

The ONLY outboard engine to ever win an EPA award for clean technology is a DFI 2-stroke.

In fact, the emissions of DFI 2-stroke engine made by BRP were cleaner than the much vaunted four stroke offering from Mercury Marine when they first came out.

Here's what George Broughton, director of Engineering, Boats and Outboard Engines Division for BRP says on the subject:

[quote]"Oil isn't a big player," says Broughton, "because the amount burned is about 1% of the total intake charge, and it never mixes with the gasoline." (The average user of a 50-hp E-TEC will go through two quarts of oil per year.) Hydrocarbons are the predominant pollutant, a portion of which are scavenged and burned in the next combustion cycle. When emission standards tighten, Broughton will be ready with a simple reduction catalyst he terms, "1970's technology." Right now, the engine is clean enough to pass California's 2008 standards.

Broughton doesn't claim E-TEC technology might have saved the automotive two-stroke, but he does suggest Detroit's obsession with preventing the lubricating oil from being burned during combustion sent them down the wrong path. "Their concentration on retaining an oil sump, oil scraper rings, and relying on plain bearings instead of roller bearings," he theorizes, "increased the amount of oil burned, which harmed emissions performance." And it may be another reason why automotive two-stroke emission performance degraded over time. "The E-Tec actually gets cleaner as it progresses through the EPA test," he says. "And we never have to worry about the potential for secondary pollution when changing the oil." [quote]

Source: http://findarticles.com/p/articles/mi_m0KJI/is_6_115/ai_103990207/

posted 11-01-2010 11:15 AM ET (US)            

Also, given the date of the article, Broughton may no longer be in the position that he was at the time it was published.

I take no specific sides on this "cost to the environment" topic, other than to posit that neither owners of modern 4 stroke nor DFI 2-stroke engines should have significant qualms about the emissions of their engines (assuming they keep the engine in good repair).

posted 11-01-2010 11:30 AM ET (US)            

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Compared to a similar 2004 four-stroke engine, carbon monoxide emissions with Evinrude E-TEC are typically 30 to 50 percent lower; and at idle are lower by a factor of 50 to 100 times. In addition, Evinrude E-TEC emits 30 to 40 percent less total particulate matter on a weight basis than a similar “ultra-low emissions” four-stroke outboard. Furthermore, oxides of nitrogen and hydrocarbon emissions for Evinrude E-TEC are similar, if not lower, than a four-stroke outboard.

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The 30 to 40 percent less particulate matter is what I found interesting regarding cost to the local environment. Basically, they're burning the oil and still have fewer particulate emissions than comparison 4 strokes of the time.

You don't have to believe it - but the funny thing about facts is that they are independent and not respecters of belief.

posted 11-01-2010 11:46 AM ET (US)            

However, I realized that I didn't address the implied question about emissions into the water.

I don't have references, but my understanding is that because of the DFI technology, all of the fuel is burned in the combustion process (in a well tuned engine). Therefore, there is no waste oil/fuel being added to the environment. The only thing entering the water and air environment is the exhaust (which is measured by the EPA and discussed above).

You could argue that cooling water may be contaminated with exhaust, but then you'd have to argue that a four stroke is more polluting than a DFI, because their emissions happen to have more particulate matter, etc.

What I'm interested to see, in the future is a DFI 4-stroke motor. Will one of the other manufacturers license E-TEC injectors for use on a DFI 4-stroke? So far, BRP seems to be keeping the technology to themselves, for use on their snowmobiles and other recreational products.

I think that an E-TEC injector could be an important component in a very strong DFI automobile offering from Ford or GM. Probably not GM, given Mercury Marine's relationship with them for Mercruiser blocks. Hey, a guy can dream, right?

posted 11-01-2010 12:07 PM ET (US)         

But then the four stroke still uses less gas...

posted 11-01-2010 02:04 PM ET (US)            

See www.evinrude.com/Content/Pdf/neutral/performanceReports/PE458.pdf & www.yamaha-motor.com/assets/products/otb/bulletins/ bulletin_4stroke_midthrustjetport_al_sa669a.tmp.pdf

If you ran an F115 at 1000 RPM for long periods of time, you would probably have to change your 4 to 6 quarts of oil more frequently than the maintenance schedule calls for. Lets say its every 50 hours instead of 100. So every 50 hours, the F115 will use about 1 to 1.5 gallons of oil and 18 gallons of gas. If you ran the E-TEC 115 at a 50:1 oiling rate for that 50 hour period, you'd burn approximately 9 gallons of gas and 0.2 gallons of 2-stroke oil.

If we went the full 100 hour service interval, the F115 would have burned 36 gallons of gas and used 1 to 1.5 gallons of oil and an oil filter. In that same period, the E-TEC 115, 18 gallons of gas and 0.4 gallons of oil. And it would have gone a further distance too.

So, you see, depending on the circumstances, you cannot generally conclude that "a 4-stroke still uses less gas."

Regarding the question "what is the fate of burned two cycle oil? Water quality?.....", here is an interesting read ==> members.iinet.net.au/~pauldawson/IAME-57_Emissions-a-sml.pdf