Newey: Only a works Mercedes and possibly a works Ferrari can win

Design guru Adrian Newey has admitted he is worried that planned rule changes in Formula 1 are not going far enough.

Reportedly frustrated at the restrictive chassis rules and the overly engine-dominated formula of the moment, the Red Bull designer has taken a step back from F1.

"F1 is quite high pressure," he told the The National newspaper. "If you do it year after year, it can be quite exhausting. So I just felt I needed a little bit of a break and I have just stepped back a little at the moment."

It has been suggested the 57-year-old's interest may be reinvigorated by the new rules for 2017 and 2018, with the cars to become faster and F1 authorities also determined to improve the current engine situation.

The engine situation, Newey said, is the biggest problem, "On top of that if you take the engines built by Mercedes or Ferrari, when they supply those engines to their customer teams, the customers don't get the same engine -- not in the software anyway."

"So we are in the position where, at the moment, only a works Mercedes, and possibly a works Ferrari, win championships and races because it is so dominated by the engine," he explained.

Newey's core competency, however, is chassis design and aerodynamics, and the sport has resolved to make big changes to the rules for 2017.

But the Briton fears the new rules will not go far enough, "Regulation changes give that opportunity to do something different. However, with the regulation changes that are being talked about for 2017, they are actually not that different to what we have now."

"Slightly wider tyres. Slightly revised aerodynamics regulations. No really fundamental differences," warned Newey.