Jun.11 (GMM/Inautonews.com) Eric Boullier has tipped Mercedes to compromise over the current engine rules.

Christian Horner, boss of the struggling Red Bull team, said this week that if the so-called ‘engine freeze’ rules are not relaxed, F1 must be prepared to wave “goodbye” to Renault.

A complex ‘token’ system is giving Ferrari, Renault and Honda a chance to catch up to dominant Mercedes during the 2015 season, but that loophole has been closed for 2016.

Not only that, the amount of allowed out-of-season development also tapers off for 2016 and beyond.

Asked if Mercedes will agree to tweak the rules, Horner said: “They don’t have to obviously but it is at a precarious point in terms of Renault’s commitment to the future.”

Also notably struggling under the existing regime in 2015 is Honda, the Japanese manufacturer who returned to F1 this year in partnership with McLaren.

But McLaren boss Boullier tipped Mercedes to “listen” to the concerns of its rivals who are pushing for rule changes.

“Honestly, they are (listening) already,” he said.

Indeed, Boullier was among those who attended the conspicuous ‘gang of four’ meeting last Friday in Montreal, also featuring Mercedes, Ferrari and Red Bull.

“Having spoken to Toto (Wolff) and Niki (Lauda), they are concerned about formula one. I’m sure there is some room to change if you look at the overall picture,” he said.

McLaren-Honda has admitted it would benefit from any freeing up of the current engine rules restrictions.

“I’m pretty sure Renault would feel the same way,” managing director Jonathan Neale said recently.

“They’re investing in the sport, they’re a big organisation, it’s important for their brand as well that they have some degree of glide-path on this.”