That large and heavy CNG tank is in place because of the original estimates for what it would take to run a snowmobile for 100 miles (a requirement of the competition), but the team told me it will be replaced with a smaller one in the future. Last year the snowmobile operated using an Arduino microcontroller on top of the stock engine computer, but now that's been changed too, for a custom ECU that allows for more tuning. To make the handling better even with the sled's extra size and weight, the team is making changes like moving the tank forward for a better center of gravity, and stiffening the rear suspension.

Judging from the video, even with the extra size, snowmobile riding is just as much fun as with any other machine, and by switching to other energy sources, it could be more environmentally friendly. This CNG sled puts out far less emissions than gas, and proposed gas pipelines could make the fuel widely available in Maine. There are other ideas out there -- some teams are working on improved tuning of gas engines for better efficiency, exhaust gas recirculation, and using diesel or electric engines -- you can see them riding out in this year's competition below.