Since gas prices are becoming more of an issue, we should cover some of the ways to improve the fuel economy of most any and every snowmobile.
For starters, slow down. The amount of fuel it takes to propel a sled at higher speeds is not linear, it is exponential. The biggest break point on a two-stroke is knowing at what RPM the powervalves (if so equipped) open and close. Operating the sled in the “low port” mode with the powervalves closed is going to provide huge gains in fuel economy (this is one main reason why the Ski-Doo 800R and now the 600 H.O. E-TEC models fitted with the eRAVE system get such good fuel economy as they have a three-position valve program, helping them to get better fuel economy than many four-stroke models.)
Another good practice is to use your brakes less, as using the brakes turns your momentum into heat. Instead, anticipate and let off the throttle slowly and coast to your desired stopping point instead, which is even better than using the engine braking through downshifting clutches (both methods are better than grabbing a handful of the brake lever).
Keeping your sled on a packed path instead of breaking trail is yet another proven method of saving fuel. This is pretty basic, but your sled won’t have to work so hard to get through the snow. Hardpacked trails always let you get far better range than fresh snow, or wet snow. When the snow gets wet, it increases the rolling resistance and amount of energy needed to maintain your speed.
Usually, a lower windshield is going to give you a higher top speed and reduce the wind resistance, leading to better fuel economy. Not always. Consider this one carefully, but anything that reduces your sled’s wind resistance is going to help. Sleds lower to the ground with less suspension travel are generally going to have less wind resistance than tall sleds that catch a lot more air.
With single-ply tracks coming into favor, a lighter track is going to also help your fuel equation. And, a track with lower lugs is going to not catch as much air, but it’s also not going to catch as much snow. Balance the track lug height with the need for traction for where and how your ride.
Another thing to consider is (most often) adding performance parts actually boosts fuel economy. The reason this is true is because the sled typically becomes more efficient than it was in stock form. Therefore, you are typically using a lower throttle position when cruising. Also, the sled is typically tuned closer to optimum and this will add fuel economy.
Another spin off of this would be making sure your clutches are in good condition. Worn out clutch components can cause the clutch to bind and the engine will eat more fuel transferring the power to the ground. This is true for the rest of the chassis as well. Make sure the drive chain is tensioned properly, and not too tight. Most obvious is to run the track as loose as safely possible without ratcheting or derailing. A tight track just sucks power and fuel, so anything you can do to reduce rolling resistance is going to help your fuel economy.