The 2001 SAE Clean Snowmobile Challenge entry for the University of Idaho (UI) provided proof-of-concept for a clean snowmobile using a four-stroke engine, exhaust after treatment, and electronic fuel injection. This combination provided excellent emissions and fuel consumption performance while maintaining acceptable power and nearly acceptable noise production. The 2002 entry built on this design while focusing on improving the overall efficiency of the snowmobile. The BMW engine was tuned for high altitude operation, higher efficiency components reduced chassis losses, and additional sound damping was utilized throughout the chassis.
