My 600 is as quick to 70 as my 800, maybe quicker, due to the explosive track spin on the 8.When the 800 E-TEC first came out Doo said it was a 155hp motor. But boasted the 163.9 like it was the word of God himself. Now their saying oh never mind the 163.9 it really was 155. But where being honest now this new motor really is 165hp. Come on really!!!!!!! Fact of the matter is 95% of guys who will buy 850 hell even the 800 will never use all of the available HP the motor makes anyways. Not to mention the number one problem for a sled is traction. If your track is spinning adding more HP will never help that only make it worse.