Toyoharu Tanabe, Honda's F1 Technical Director, believes that communication and compromise were central to the manufacturer winning races and a world title with Red Bull, having previously failed to do so at McLaren.
Honda returned to F1 as McLaren's engine partner in 2015 but struggled for performance and reliability, with the two parties splitting after just three seasons.
However, when Honda joined forces with Toro Rosso (now AlphaTauri) in 2018, and the senior Red Bull outfit followed suit a year later, significant progress was made – enabling Red Bull to challenge for the 2021 title.
Red Bull and Honda combined as "one team"
Reflecting on Honda's relationship with Red Bull, and how it compared to the McLaren days, Tanabe described a "one team" atmosphere being formed across their three seasons together.
"The most important thing is communication," Tanabe told RacingNews365.com in an exclusive interview at last year's season-ending Abu Dhabi Grand Prix, which marked Honda's final race with Red Bull in an official capacity.
"Our desire is the same [as it was] to win races and win the championship. How [do we] achieve our purpose or desire? The key is to make a high-performance car, as a package.
"We discussed a lot what we wanted to do, with each other, and then made a compromised decision to make the car fast.
"We know each other very much, so it was very open-minded [and] a very detailed discussion. That discussion and then communication makes us a strong, kind of one team."
"Human sensor" Verstappen also played his part
While Red Bull missed out on the Constructors' Championship, Honda ended their latest spell in F1 with a title, as Max Verstappen edged out Lewis Hamilton for the Drivers' crown at the end of a season-long battle.
Tanabe took a moment to note Verstappen's detailed technical feedback and how it contributed to Honda's engine gains.
"I think he has a talent, he has a skill, to drive the car fast," continued Tanabe. "Not only fast, but also as a kind of sensor, a human sensor; he is very sensitive and the feedback is very precise.
"For the engine condition, he realises very small sounds or feelings – he could tell us very small things. His feedback and kind of testing was very useful for us."
From 2022, the newly-formed Red Bull Powertrains company take over the intellectual property and running of Honda's power units.In a recent interview with RacingNews365.com, Red Bull team boss Christian Horner explained that while the engines will be Red Bull branded, Honda "won't be totally invisible".
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