Dr Helmut Marko has hinted strongly that Red Bull is giving serious consideration to a switch to Honda power for 2019.
Currently, the Austrian outfit is weighing up between staying with Renault or moving to the Japanese manufacturer.
Already for 2018, Red Bull decided to install Honda engines at its second team, Toro Rosso.
"We let Honda explain everything they wanted to change for this year," Marko told Bild. "That convinced us.
"I am even learning a few Japanese words, especially so that we can have dinner together in the evenings."
Some worry that while Red Bull Racing makes arguably F1's best chassis, it is Renault power that will stop the team from winning the 2018 title.
"Red Bull has taken a step, but it takes a lot of money and energy to reach Mercedes," Frits van Amersfoort, Max Verstappen's junior series boss, told Het Laatste Nieuws.
"It is mainly about Renault and what it can do with the engine, and I'm pretty sceptical. I do not believe the euphoria that arose after the Barcelona tests.
"Sixteen million Dutch think Max is going to be world champion, but we'll only find out in Australia."
The Australian Grand Prix gets the 2018 championship underway on Sunday.
