Drafting (sometimes known as slipstreaming) is a technique in Mario Kart 64, Mario Kart DS, Mario Kart Wii, Mario Kart 7, and Mario Kart 8 that allows for a short speed boost. In its first iteration in 64, drafting is more subtle: there are no lines to indicate if it is being done correctly, the wind is gray instead of blue, and the speed boost is brief. In the later two games, when trailing behind another racer, blue lines appear around the player's kart or bike. If the position is held for about 3-5 seconds, the player will be surrounded in a blue wind with a modest speed increase. The boost lasts for about 3 seconds, or until the player hits a wall, obstacle, racer, or item. It can last as long as a Mushroom boost.
While tricky to do on curves, this is incredibly useful on straightaways. However, this can be a risky maneuver- racers looking to receive a speed boost can be easily flipped over by held items. It is better to use this on lower-leveled CPUs than real racers, although it could decide the first lap if used at the very beginning.