Mercedes’ full F-duct solution is not ready to debut in Barcelona this weekend.
The Brackley based team used an initial iteration of the blown rear wing concept in Shanghai two weeks ago, but unlike McLaren’s pioneering version it was not operated by the driver.
Instead, air was ‘flicked’ at increasingly higher speed through a slot in the rear wing.
Team boss Ross Brawn said Mercedes was “working on the proper system” at the same time and hoping it will be ready for the Spanish grand prix.
But according to Germany’s Bild am Sonntag newspaper, the final solution is not ready for round five of the 2010 world championship.
Mercedes will now aim to have the full F-duct up and running in Turkey, with Brawn admitting “there’s no point in having it” on the twisty streets of Monaco in two weeks.