Environmental impact Snowmobile

student-constructed sae clean snowmobile @ imagine rit 2017.

most snowmobiles still powered two-stroke engines, although alpina , yamaha have been using four-strokes since 2002 , 2003, respectively. however, in last decade several manufacturers have been successful in designing less polluting motors, , putting of them in production. yamaha , arctic-cat first mass-produce four-stroke models, less polluting two-stroke machines. alpina offers 4-stroke efi engines equipped catalytic converter , dual oxygen-probe. bombardier s e-tec two-stroke motors emit 85% less pollutants previous carbureted 2-strokes. polaris has developed fuel-injection technology called cleanfire injection on 2 strokes. industry working on direct-injected clean 2 strokes better in terms of nox emissions.

independent researchers, undergraduates , graduate students participate in contests lessen impact of emissions snowmobiles. clean snow mobile challenge held yearly @ michigan technological university regrouping entries universities across united states , canada. of participants in recent years have been École polytechnique de montréal quasiturbine engine , students École de technologie supérieure of uqam less polluting two-stroke engine using e85 , direct injection.

noise

maximum noise restrictions have been enacted law both production of snowmobiles , aftermarket components. instance, in quebec (canada) noise levels must 78 decibels or less @ 20 meters snowmobile path. of 2009, snowmobiles produce 90% less noise in 1960s there still numerous complaints. efforts reduce noise focus on suppressing mechanical noise of suspension components , tracks. arctic cat in 2005 introduced silent track technology on touring models such t660 turbo, bearcat, , m-series sleds. ski-doo has since used comparative silent track technology on models.

the use of aftermarket exhaust systems ( cans or silencers ) controversial. these replace stock muffler less restrictive system claimed increase power output of engine. however, these aftermarket exhausts louder factory, being quieter open, unbaffled system. most, if not all, local snowmobile clubs (that maintain , groom trail systems) not recommend them because of noise. local , state authorities have set checkpoints on high-traffic trails, checking excessively loud systems , issuing citations. typically these systems installed on 2-stroke powered machines (giving distinctive braap sound); however, in recent years aftermarket companies have released silencers 4-stroke models well.