Red Bull chief designer Adrian Newey believes that the current advantage held by engine manufacturers in Formula 1 has left the sport in an unhealthy position.
Red Bull claimed four successive world titles during an era when an aerodynamic advantage was required, but the emphasis has shifted to engine superiorty since V6 power units were introduced at the start of 2014.
Red Bull has not won a race since Daniel Ricciardo's victory in the 2014 Belgian Grand Prix, with Mercedes having won 23 of the 26 Grands Prix in that period, the other three having been claimed by Ferrari.
"For me, what’s unhealthy about F1 at the moment is that it is engine dominated," Newey told The National.
"The chassis regulations are very tight, the engine regulations are very free. 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. The software becomes very important now.
"So we are in this position where Mercedes have a very good, very powerful engine. Their customer teams don’t get the same specifications. So it is difficult for their customer teams to beat the Mercedes team.
"Ferrari have an engine not quite as good as the Mercedes, but still a good engine. But the same problem with their customer teams."
Newey believes that Formula 1 is in a situation where only Honda will be able to challenge Mercedes and Ferrari across the near future.
"Honda and Renault, so far, have been quite a long way behind," he explained.
"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.
"I think that is a very unhealthy situation for Formula 1, where only one, maybe two teams, can win. Maybe Honda in the future, but not yet."
Red Bull will continue to use Renault power units this year although they will be re-badged as Tag Heuer.