I offer this for information purposes only. This past weekend, we had four REV 600SDIs running together - two are 2004 SDI Adrenalines and two are 2005 600SDI Renegades. Temperatures were very cold. Saturday morning, both 2004s' electric start would not operate. One '04 pull started, but the other would not - it's battery completely frozen, meaning no power for the electronics. Thus, two new batteries later, both machines started fine. (The local SkiDoo dealer did not have any batteries - shock, they were on back order. So, Canadian Tire filled our need.) Mileage: all four sleds ran 230km (143 miles) and used 29L (7.7 USgal : 6.4Imp gal) of gas each. There was no difference in fuel consumption of anyone of the four sleds. We had been wondering if the Renegade's larger track would offer a slight fuel mileage penality, but the good news is apparently not.