Feb.20 (GMM).- F1's governing body has told Williams its exhaust solution for the newly-launched FW35 is not legal.
It was already believed a similar solution for the Coanda-effect exhaust on Caterham's 2013 car definitely falls foul of this year's rules.
But Williams' chief designer Mike Coughlan said in Barcelona on Tuesday, where the team's new Renault-powered car was revealed and tested for the first time, that he was confident the FW35 complied.
In fact, the two solutions were very similar, but the Williams one more cleverly exploited a loophole about aerodynamics-influencing apertures.
The FIA's Charlie Whiting was at the Circuit de Catalunya on Tuesday, and according to Auto Motor und Sport correspondent Michael Schmidt, "it was rumoured Williams had got the FIA's blessing" before revealing its solution.
"It may be a technicality," Mercedes' Ross Brawn is quoted as saying, "but if you read the rules word for word, Williams is on the safe side."
But Schmidt reported: "This is not the case."
Schmidt even quoted Whiting as saying both the Caterham and the Williams solution indeed "violate" the rules.
The FIA states that an exhaust's primary objective is not to affect the aerodynamic performance of the car, and concretely to this case, to avoid a rule bypass, it deems that the sides of the Coanda channels are not allowed to converge in any way, meaning that they must be vertical or slope outwards.
A Williams spokesperson confirmed: "The team spoke with the FIA this morning, which is when they gave us their view.
"The team are now seeking further clarification on this and a decision as to whether this design will be carried forward will be made before the first race."