The stututu sound comes from turbocharger flutter, the rapid chattering heard when compressed air surges back through a turbo after the throttle closes. Car enthusiasts gave it the playful stututu nickname because it imitates the noise, and clips of it spread through automotive videos, short-form edits and meme soundboards. It is now a shorthand for turbocharged cars in general, used far beyond serious tuning content to add humour and attitude to racing clips, reaction videos and gaming edits.