Adrian Newey has mocked Formula One's new engine rules, with the Red Bull designer claiming they have produced slower cars without achieving the intended green goals. Speaking before Sunday's Bahrain Grand Prix. Newey, who devised the cars that won Red Bull the past four drivers' championships, said the new 1.6 litre V6 turbo-hybrid engines have increased costs and slowed down the cars for little benefit.

"The cost has gone up hugely to create this," Newey said. "If you put that cost into weight saving, you might be better off in many cases, so to automatically say that this is some huge benefit for mankind is taking a bit of a big leap.

"There is a relationship between cost, weight, aerodynamics, all sorts of factors, if you're going to go into road relevance. How you weigh that, how you proportion it, is impossible for an open-wheeled single-seater [car]. It's a very different beast."

The engines have been criticised for both creating a muted sound and for producing a processional style. "Formula One should be about excitement," Newey said. "It should be about man and machine performing at its maximum every single lap. OK, they're using 50 kilos less fuel [per race] but they're going a lot slower to achieve that."