I have a GTX500ss and my Son has a MXZ 500ss trail with 96 studs, both 2005's and after the first tank of ski-doo oil we switched to BM. Within 2 tankfuls of fuel, I believe we noticed a differance. My son's milage shot up to 16-19 mpg and mine was 15-18 mpg riding 2-up consistantly. My son's driving isn't exaclty light on the throttle either. Alot of that driving was at above 60- 70 mph speeds. I believe the smoking went down, but I can't really recall how much it smoked prior, it just seems better now. So far I have all good to say about BM.revman600rj said:Has any one used Blue Marble Oil yet? If so did it help the gas milage like the dearler said it would?