Shanghai - Jenson Button will be out for his third straight season win at the Chinese Formula One Grand Prix on Sunday now that his fast Brawn GP car has been declared legal.
The governing body FIA said on Wednesday that diffusers used by Brawn, Toyota and Williams meet F1 rules, forcing other teams to play catch-up which could take several weeks.
The diffuser is an aerodynamic feature which channels air out of the back of the chassis. It affects the car's downforce which in turn enhances speed and performance, allegedly making the car half a second faster than others over one lap than one without the diffuser.