Red Bull motorsport adviser Dr Helmut Marko says Formula 1’s engines rules are heading towards a sensible outcome but feels “fans should be king” in the decision-making process.

Red Bull has continually complained about its underperforming Renault power unit compared to the dominant Mercedes engines in the V6 hybrid era but Marko was pleased to see the French manufacturer’s improvements throughout 2017.

Red Bull will run TAG-Heuer-branded engines supplied by Renault until the end of 2018 but team principal Christian Horner has hinted at an Aston Martin engine partnership if the regulations suit the British manufacturer, but any deal won’t come into action until the next regulation changes in 2021.

Marko has faith in the future direction of F1 engines, with thoughts shifting towards the 2021 rule changes, and is keen for the rules to be simplified for both teams and fans to appreciate. New F1 owners Liberty Media has made early suggestions for the 2021 engines to drop the MGU-H unit while standardising the energy store and control electronics.

“It is going in the right direction. Clearly it could not go on like it was,” Marko told “The rules are too complicated. The fan should be king, they should easily understand what is going on – and that is not possible with the current engine rules.

“Of course I also see Toto Wolff’s viewpoint: if he loses his engine he loses most of his advantage – so he is fighting against it. How will it end? I think we will get technically simpler engines, less expensive but more noisy. We are moving there.”

Reflecting on Toro Rosso’s new engine deal with Honda from 2018, Marko has repeated his confidence in the Japanese manufacturer getting on top of its unreliability issues and producing a competitive power unit in F1. It has been rumoured if Honda can turnaround its fortunes in 2018 it could also secure a deal to supply Red Bull if its existing Renault partnership is ended next season.

“We are very happy with the Toro Rosso and Honda cooperation,” he said. “Toro Rosso will put all its efforts into making a competitive chassis. We do believe in Honda - otherwise we wouldn’t have made that deal. I am very impressed with the facilities that they have - and their determination to win.

“It is just a matter of bringing everything together and we believe that this moment will arrive sooner than everybody is expecting. We will observe very closely, beyond 2018 everything is open.”