double post, sorry.http://www.epa.gov/otaq/regs/nonroad/2002/f02033.pdf
"How do these engines and vehicles affect air quality?
Nationwide, these engines and vehicles are a significant source of air
pollution. In 2000, they accounted for about 9 percent of national hydrocarbon
(HC) emissions, 4 percent of carbon monoxide (CO) emissions, 3
percent of oxides of nitrogen (NOx) emissions, and 2 percent of particulate
matter (PM) emissions from mobile sources. If left uncontrolled, by
2020 these engines will contribute 24 percent of national HC emissions,
6 percent of CO emissions, 9 percent of NOx emissions, and 5 percent of
PM emissions from mobile sources. These estimates for 2020 show
higher relative emission levels, both because of expected growth and
because emission controls for cars, trucks, and other emission sources
will substantially decrease total emissions."
This is for snowmobiles, ATVs, and dirtbikes, as well as large industrial spark ignition engines. That basically means farm vehicles, and forklift type devices. Damned EPA doesn't have good stats for just the recreational vehicles. Anyways, these things are all pretty much unregulated now, and despite their tiny numbers and usage compared to say, automobiles or onroad diesels, they produce 10 percent of HC emissions. Thats a scary figure.
Compared to a ULEV vehicle (Say, a 2003+ Honda Civic or Accord, I4 or V6) a 2 stroke snowmobile produces nearly 100 times as many pollutants per unit of time operated.
Current 4 stroke snowmobiles produce about 35 times as many emissions per hour. That means, put 10 hours on your pre 2006 regs 4 stroke snowmobile, and its similar to driving a new car for 350 hours. Or, driving a new car cross country about 9 times.
PS- I'm not some bigass treehugger. I'm actually an auto enthusiast. I believe in reasonable emissions controls. Evaporative controls cost about 50-75 bucks per unit, and they weren't mandated on onroad motorcycles till this year. Interestingly, EPA hasn't supported enforcement action to its typical extent since a certain political event in 2000... Not a political statement, just an observation.
Originally Posted by Philadelphia Inquirer paraphrased
In the past, the EPA under the first President Bush averaged 195 pollution citations a month; the Clinton EPA averaged 183. Bush's EPA, as of Decmeber 2003, had averaged 77 a month, and the number has dropped every month. [Philadelphia Inquirer, 12/9/03]