They say grooves are slower than slicks. I run on a small tight track. Turns have a 44' radius. Saturday night it was slick. Kart was pushing bad off 1 and 2. I almost wish i would have put the groove tires on. I know some of the tracks on you tube grooves probably wouldn't work but on this small track with tight turns how much difference in lap time there would be between grooves and slicks.