Snowmobiling tips

    For many of us, the start of winter means that it’s time to start up the snowmobiles and disappear for the season into the wintry Maine woods. But before we take that first ride, let’s consider how to minimize the environmental impact of all that fun.    Studies have found that a single snowmobile can emit as much pollution in one hour as nearly 100 cars! What is it about some snowmobiles that makes them so dirty? The answer is simple: the two-stroke engine. The two-stroke engine is a small, powerful engine used to run many common types of equipment, from chain saws to snowmobiles. The “simple” design of the two-stroke makes it extremely inefficient and very dirty. Unlike automobile engines, two-stroke engines require that lubricant oils be mixed directly with gasoline before combustion takes place. The combustion of this oil produces a smoky exhaust, heavy with particulate matter — a pollutant that can contribute to and exacerbate respiratory and cardiac illnesses.
    If a new sled is in your future, you’ll be getting a cleaner ride. Beginning in 2006, the US EPA required all new snowmobiles to meet certain standards that reduce carbon monoxide and hydrocarbon emissions. Snowmobiles manufactured beginning in 2010 will have to meet even more stringent standards. These requirements apply to both two- and four-stroke engines so any new machine will be cleaner than an old one. Most snowmobile manufacturers now offer four-stroke models, which emit significantly less air pollution than older two-stroke snowmobiles and increase fuel economy by a whopping 35 percent.
    But if you need to get a few more years out of your existing two-stroke machine, there are a few ways to make your engine run cleaner. One option is to use synthetic, low-emission lubricant oils. These lubricants are not only designed to burn cleaner, but will also improve the overall performance of the snowmobile. There are even a few lubricants on the market that are biodegradable and will not pose a threat to surface or groundwater if leaked or spilled directly onto the ground. Bio-lubes made from soybean oil provide all of the above benefits and are also renewable – another environmental plus.
    Another thing we can do now to make our two-stoke snowmobiles run cleaner and more efficiently is to make sure that they are properly tuned, by a qualified mechanic, before the beginning of each snowmobile season. This strategy helps to ensure maximum fuel efficiency and performance out of our sleds, while decreasing overall emissions.
    Finally, an add-on carburetor and catalytic exhaust system proven to reduce emissions of hydrocarbons and carbon monoxide by 75 percent – 80 percent is available. This technology increases overall horsepower and improves the fuel economy of the snowmobile.
    Whether we purchase new, cleaner snowmobiles or take steps to make older two-stroke engines more environmentally friendly, we can do our part now to run cleaner over the landscape. So, let there be snow!
    This column was submitted by Nathan Howard, a transportation planning analyst with the Maine DOT. In Our Back Yard is a weekly column of the Maine Department of Environmental Protection. E-mail your environmental questions to infoDEP@maine.gov or send them to In Our Back Yard, Maine DEP, 17 State House Station, Augusta, ME.