2.8 pounds per horsepower. Gravity couldn’t be reached for comment. If you live to make molehills out of mountains, this is the sled you've been waiting for. Built on the REV-XP platform with the 151 horsepower 800R Power T.E.K. engine, the 2008 Summit® X is the first-ever mountain sled to break the 3 pounds per horsepower barrier. At 429 pounds, it's almost 50 pounds lighter, yet 37 percent stronger, than its predecessor. Unbelievably agile and flexible, thanks to the REV-XP chassis. In other words, it's a sled that's destined to redefine mountain riding - one highmark at a time.