Adrian Newey, who is frustrated with F1's new regulations, fears the sport could face "grave danger" unless there's a "rethink" about the rules.
Although last weekend in Montreal, Red Bull Racing signed Newey onto a new "multi-year" contract, the technical chief won't be spending much time focusing on F1 in 2015.
Instead the Brit will be concentrating on outside projects, admitting he has grown disillusioned with Formula 1's "very restrictive" regulations.
Some of the rules that he is unhappy with relate to the new 1.6-litre turbocharged V6 engines and the ERS package.
This has been Red Bull's downfall this season as the team's engine supplier Renault is lagging behind Mercedes in both speed and reliability.
And with an engine design freeze on the horizon, Newey fears some engine manufacturers may be left with an under-performing unit.
"The current set of regulations are engine orientated," Newey told Autosport. "At some point in the coming years presumably that will settle down.
"There is grave danger, with the freeze happening progressively over the next 18 months, because it's not apparent if one manufacturer ends up with an advantage as to what happens at that point.
"Is that advantage maintained for ever more, in which case the rest of us give up?
"It doesn't seem to me to be a particularly satisfactory situation at the moment. The regulations need more of a fundamental rethink in my opinion."