My kart weighs 310 & 330 two drivers. I'v run evinco Blues used and new tires. 7" rears. Got 9 hrs track time. On the 1st set. Kart old Birel, stiff chassis. It's getting quicker @ pats acres as we get more used to it. Which tire to speed money on to go the fastest. I've heard evinco yellows r the fastest! ?