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.
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.
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.
"To come up with a formula that's about a very short sprint race, an hour and a bit, using a single-seater open-wheel car, and saying that's then relevant to the road is a very complicated leap in my opinion.
Symonds said: "One can look at where we would be if we hadn't introduced something like that. We would really be standing out and leading ourselves open to criticism. "We should be very proud of what we've done. We had pretty efficient V8 engines before; we have super-efficient V6 engines now, with technologies we will undoubtedly see on road cars in years to come. So we should be celebrating what we've done.
"Has the racing changed because of it? I don't really think so."There might be some early teething problems but we've had two races, it's a very immature formula at the moment. Let's see how things pan out but I am pleased with the fact that what we're doing is relevant to society."