STR drivers still waiting for double diffuser

It will likely be yet another two races before a 'double diffuser' will be added to the rear of Toro Rosso's 2009 car.

We reported last month that, while parent team Red Bull Racing introduced the aerodynamic concept for its Adrian Newey-designed car at Monaco, a similar piece would not be added to Toro Rosso's Ferrari-powered single seater until after the Turkish Grand Prix.

Swiss driver Sebastien Buemi said at the time that the modifications necessary for the diffuser were "quite massive", and it now emerges that there will be a delay of at least two more races until the piece might be ready to debut.

Germany's Auto Motor und Sport said the STR4 might have a double diffuser in Hungary late next month, depending on the success of the development on Red Bull's nearly identical chassis.

"I want to see how the diffuser works before we spend that much money," boss Franz Tost is quoted as saying.