One of the E-TEC’s big selling points is that it is environmentally friendly. At the time it was introduced, it was the only 2-stroke engine that could meet California Air Resources Board (CARB) 3-Star pollution standards. Since then, the Mercury Optimax and Tohatsu TLDI engines have also achieved 3-star ratings.
In this post we look at some of our experiences in this area. We’ll be up-front and let you know that much of this post is based on information that might be out-of-date, or subjective in nature, although hopefully well-reasoned. The problem? This is a very touchy subject, and in some cases information that was published has disappeared from the Internet, or has not been updated in a number of years. Why? We can only guess…if you’re a big conspiracy theory person, this should be right up your alley.
Past posts covered performance and fuel economy, and reliability/durability/serviceability. The next post will cover our E-TEC’s total operating costs.
Pollution or not?
Carbon footprint
Exhaust soot
What would you think if you saw this after a day of fishing?
Oily exhaust from a 2-stroke? That’s what we thought initially. It’s not. It’s non-oily carbon soot. You can wipe it off with your finger, with no residue. As best we can tell, the deposits are exhaust soot that builds up on days when we spend a lot of time idling. For us, that occurs when we wind up stopping on a lot of kelp paddies. We typically just leave the engine in idle while we fish.
When we first discussed this with a mechanic, the thought was that the engine was running cold. Subsequent diagnostics showed that was not the case.
Is this bad? Probably not. Soot is basically carbon particulate, which is inert. It’s not going into the atmosphere as carbon dioxide.
Burning 2-stroke oil “E-TEC style” versus “Recycling” 4-stroke oil
One of the arguments for 4-strokes has been the idea that recycling the used engine oil is more ecologically sound than burning oil in a 2-stroke. I suspect that most consumers, like myself, were under the impression that the oil was somehow reprocessed for use in some other lubrication application.
Not surprisingly, that is NOT the case. A study from the American Petroleum Institute in the late 1990s indicated that a relatively small percentage (around 11%) of recycled oil is cleaned up and reused as a lubricant. The majority of the oil (78%) is converted into fuel oil and burned in furnaces, or introduced back into the environment as components in asphalt and other petroleum-based products. Ironically, the State of California used much of the recycled oil as weedkiller, spraying it along the roadside.
Where do these statistics come from? It started with this web page from SynLube, which I discovered while researching a previous article on 4-stroke versus 2-stroke outboards. Unfortunately, many of the links mentioned in the article are no longer available, including some of the articles which I personally read. When searching some of the related websites, it is apparent that no organization has published any similar surveys on recycled oil since then. Or if they have, access is limited.
One thing is true – current economic conditions and crude oil prices have made the market for recycled oil even worse than when Synlube first published its article. So I would suspect that if anything, the situation is even worse regarding how much used oil is actually recycled.
Given the above, does it make any difference whether outboard oil is burned cleanly in an E-TEC, or burned as heating fuel? Or sprayed on the roadside as weed killer? I am inclined to think that it’s a push, although it seems to me that burning it in a high-compression engine would result in less pollution than burning in a home furnace….
CO Emissions
A CO warning decal
One of the hot topics in boating pollution is not Carbon Dioxide emissions, but Carbon Monoxide emissions instead. Not because of global climate change (although it contributes), but because of safety issues.
CO is a colorless, odorless gas that can kill. It is a product of incomplete engine combustion. There have been numerous cases of boaters dying from CO poisoning, either from unknowingly inhaling the gas, or passing out from the gas, falling into the water, and drowning. Check out this article from the US Coast Guard CO Info
Old-style 2-cycle outboards were probably the worse offenders. 4-strokes produce much less CO, and according to Evinrude and the EPA, E-TECS produce even less. For most of us, this is not a deciding factor when buying an outboard, but it should be something you consider.
The Bottom Line…
If you look at the total picture (that is, including where the oil from a 4-stroke oil change actually goes), I am convinced that the E-TECs have no more impact on the environment than a 4-stroke; probably slightly less.
Next Up…
Our final installment – E-TEC Total Cost of Operations…