Propeller Rally was a new Mario Kart World Knockout Tour route added in version 1.8.0.
Knockout Tour is World’s long-form survival race. Instead of stopping after each conventional circuit, racers travel across connected sections of the game world and must remain high enough in the standings to avoid elimination at checkpoints.
The 1.8.0 update added Propeller Rally alongside Turnip Rally. These routes increased the variety of paths available in the mode, which had already been expanded through earlier updates after the game’s launch.
The word “Rally” is important because these are route-based Knockout Tour events, not ordinary three-lap courses. VS Race provides the more traditional single-course format, while Knockout Tour emphasizes continuous movement, changing environments and survival through successive checkpoints.