Charlie Whiting has admitted F1's governing body will likely have to change the exhaust rules yet again for 2013.
Led by technical delegate Whiting, the FIA clamped down hard for this season on the sort of 'exhaust blown diffuser' layouts that had become widespread last year.
New exhaust layout rules, combined with new restrictions on engine mapping, have made it much more difficult for teams to achieve an aerodynamic effect from the fast-moving hot gases produced by the engine.
"We are aware, however, that they (the teams) will do as much as they can to direct the exhaust gases down into the area where they want them," Whiting said in the FIA's Inmotion magazine. "I think (the effect) will be 20 per cent of what they had before."
Among the cleverest and most effective solutions for the 2012 rules has been seen on the Sauber, and so Red Bull has followed suit and it is believed Ferrari will be next.
But Whiting hinted that the 2013 rules will clamp down even harder: "I suspect we'll have to have another go at it in 2013," said the Briton.
He admitted, however, that the egg cannot be unscrambled.
Referring to the jet of high-speed gas emanating from the exhausts near aerodynamic surfaces, Mercedes' Aldo Costa confirmed to Germany's Auto Motor und Sport: "You can't ignore a gift like that."
Charlie Whiting explained: "It is a classic case of not being able to unlearn things once they have been invented. The engineers know that there are benefits to be had and there is still some scope for development in this area. And we can't wipe the memories of the engineers like a computer, can we?"