University of Idaho's low-speed flex fuel direct-injected 797cc two-stroke rear drive snowmobile.

The University of Idaho’s entry into the 2012 Society of Automotive Engineers (SAE) Clean Snowmobile Challenge (CSC) uses a Ski-Doo XP chassis with a lowspeed 797 cc direct-injection two-stroke powered snowmobile modified for flex fuel use on blended ethanol fuel. A batteryless direct injection system was used to improve fuel economy and decrease emissions while maintaining a high power to weight ratio. A new tuned exhaust design was used to lower the engine speed while maintaining a peak power output of 79 kW (106 hp). Noise was reduced by running the engine at a lower speed, and by strategically placed sound absorbing materials within the engine compartment. A muffler was designed that reduced exhaust noise and improved engine emissions without greatly reducing power output. A rear drive system was designed to improve drive train efficiency, and the snowmobile entered the 2012 SAE CSC competition weighing 281 kg (620 lbs) wet, achieving 9.35 km/L (22 mpg) running on blended ethanol fuel, with an EPA five-mode emissions test score of 196 on E10, and a predicted J-192 sound magnitude score of 78 dBA.