The sledRacer.com crew ran into Russ Ebert at the USCC Race School this past weekend. As so often happens with Russ, we ended up in a technical discussion, this time regarding fuel tanks. One of the emissions compliances OEMs have to make regarding all sleds built is fuel tank permeability. Clear fuel tanks, while the racer’s friend, are especially susceptible to this rule because of UV rays and other stuff we don’t understand affects the clear plastic moreso than black (or certain other colors). This is why race sleds today have what Russ told us are called “dual laminate” tanks. Essentially they have black plastic on the outside and clear on the inside. When the Ski-Doo XP was released Doo racers learned about this and took a torch, heated up part of the tank  on their race sled (dry, of course) and scraped part of the outer black covering off to reveal the clear inner liner (and visible fuel level). A certain USCC racer just tried this on his 2010 Sno Pro 600 and alas, there was no inner liner. Cha-ching! New fuel tank. Bummer.

 Anyway, Russ went on to inform us just how fuel tanks are tested for permeability. First, the tank is weighed empty. Then, it is filled with fuel and put into an oven where it is heated to specific temperature for a specified amount of time. Then it is taken out of the oven, the fuel is dumped out and the tank is weighed again. The weight difference reveals the permeability of the fuel tank. In other words, the plastic absorbs a certain amount of fuel at a certain rate which represents how fast fuel passes through the plastic and into the atmosphere.

 So that, fellow sledRacers, is why we don’t have the convenience of clear fuel tanks on our race sleds anymore.