Mercedes GP chief Ross Brawn fears that Formula 1's attempt to ban blown diffusers next year may not have gone far enough in closing off potential loopholes for teams to continue exploiting exhaust gases.
With technical chiefs due to discuss further the issue of exhaust exits at a meeting of the FIA's Technical Working Group this week, Brawn believes attempts to restrict outfits to vertical pipe exits may not be strict enough to prevent some exploitation of the regulations.
"I don't think it is 100 per cent sorted unfortunately, and there is another meeting of the TWG," said Brawn, when asked by AUTOSPORT about the latest situation regarding exhausts.
"I think everyone, as they get more and more into it, are trying to close off the loopholes, but there is no guarantee that somebody will not come up with some scheme. It is fairly robust, but I would not say it is 100%, and I think the difficulty now is it is reaching a stage where teams will take their opportunities rather than change the regulations.
"Teams go through a period of finding the best regulations they can with good spirit and proper intent, and then you reach a stage where those regulations are fixed with the best intent. But if an engineer comes along with a good idea we have to consider it.
"In our case it is still relatively conventional, but whether someone else will come up with something dramatic I would have to wait and see. I would not say I am confident that there will not be an innovative exhaust scheme because once we have learned something you cannot unlearn it.
"The strength and performance that comes from the exhaust, using exhaust energy, is substantial, and people now have a better understanding of what they can do with exhausts/engine mapping to extenuate the effect."
Brawn's comments about exhaust regulations come at a time of great interest in his own outfit's use of airflow at the front of the car - with Mercedes GP appearing to direct air through a hole in the nose and out through the rear of the front wing to help tidy up flow under the floor.