Adrian Newey Criticism of New F1 Rules.
Red Bull design chief Adrian Newey has criticised Formula 1's new rules, saying their merit is "questionable".
The 55-year-old says the new turbo hybrid engines and fuel limits were introduced "without proper thought".
Newey said the sport should have spent more time considering whether it had gone in the right direction.
Williams chief technical officer Pat Symonds said: "I don't agree. The power-units are relevant to the future of the automotive industry."
Newey's comments are the latest in a series of public statements opposing the new rules by four-times world champions Red Bull, who have suffered a drop in competitiveness this year because their Renault engine does not produce as much power per unit of fuel as the rival Mercedes.
But he denied he was making his remarks as a result of sour grapes.
"I would have said the same thing before the rules came in," Newey said. "I wasn't asked. That's my opinion.
"I like lightweight and efficiency, and these regulations have created cars that are exceptionally complicated, quite a lot heavier.
"Complication and weight is an expense, if it brings something that's absolutely fantastic, but I do believe that should be debated."
The new rules are focused on two levels of fuel restriction - a maximum of 100kg of fuel for a race distance and a maximum fuel-flow rate of 100kg/hour. There have also been changes to the aerodynamics of the cars.
The fuel-flow rate ensures that the development of engines goes in a direction relevant to fuel efficiency - and therefore the road-car industry. Removing the rate restriction would lead development down paths that were relevant only to racing, experts say.
However, Red Bull team principal Christian Horner has proposed abandoning the fuel-flow limit because of what he claims are problems with the accuracy of the official sensors that measure it.
Newey argued that the new rules may not have been the best way to pursue their intention of driving increased efficiency in F1.
"We've gone down this route of trying to come up with a sport that appears to be road-relevant and in truth that's extremely complicated," Newey said.