U-turn

A U-turn (also written as U-Turn) is a technique in Mario Kart 8 and Mario Kart 8 Deluxe that allows the driver to quickly turn around. It can be used only in the games' Battle Mode. To perform a U-turn, the player must release the acceleration button in the middle of a drift. The vehicle will turn up to 180 degrees with a turning radius much tighter than normal steering allows, with dust being kicked up behind it.

Mario Kart 8

 * Electronic manual bio: "When drifting, release while continuing to hold  to do a U-turn."