Throttle is an installable performance-enhancing component for Extreme Gears. Its actual appearance is unknown, though it is presented as an icon on the head-up display in the top-left corner of the game screen. Its icon is a circle with a different image on each face. On the default side of its icon, it is a gray circle with a black question mark inscribed in it. When enabled, Throttle will show the icons of Ring Cap UP, GP Gauge UP and Max Speed UP.
In the game, Throttle is permanently installed into only certain Extreme Gears. When used, Throttle allows the player to choose between one of the following abilities for it to have:
Ring Cap UP: Increases the maximum number of Rings that the player can carry.
GP Gauge UP: Increases the capacity of the player's GP Gauge.
Max Speed UP: Increases the Extreme Gear's top speed.
The ability granted by Throttle depends on the face on its icon present when the player activates it; once the player has the opportunity to activate Throttle, its icon will switch between the faces of the three abilities it can grant, and the face seen when Throttle is activated will decide which mode will be chosen.
In gameplay, Throttle and its ability will be disabled when starting a new race. To activate Throttle, the player must press one of the following buttons after collecting a certain number of Rings:
Wii (remote) - sideways
Wii (remote) - forward
Wii (Nintendo GameCube Controller)
When activating Throttle, the player's Rings will be reduced accordingly by the number needed to enable it and the Extreme Gear is surrounded by an orange void, indicating the Gear Part's ability is in effect. The following Extreme Gears come equipped with the Throttle: