One of the most successful engineers in the history of F1, Newey has been a mainstay of Red Bull since he joined in 2006, contributing to the outfit's 13 world titles – seven in the drivers' championship with Sebastian Vettel and Max Verstappen plus six in the constructors'.
Having taken up different projects in the Red Bull group since 2014, Newey stepped back from the daily management of F1 technical affairs as Wache was promoted to technical director in 2018. Although he is nearing retirement, the 65-year-old Brit remains involved in designing the team's machines, and his contribution is commended as paramount to their competitiveness.
"He’s irreplaceable, yes – you cannot replace him!" Wache told Autosport. "On a daily basis, he’s not part of our process. He’s more coming from the sideways and trying to help us or challenge us on different aspects of the team – it could be mechanical design, aero or vehicle dynamics."
Newey's experience is deemed invaluable after nearly two decades at Red Bull as well as previous successful stints at Williams and McLaren, with Wache reckoning the team's stalwart has "the most experience of the full grid in terms of engineering" and agreeing he now acts as a mentor to the squad.
"You have to use him as experience, as he has less time for us," he said. "He’s more… I don’t know the word in English – when you say somebody is there to challenge one aspect of stuff. He’s not there to do the plan, to do the full concept of the car."
Asked if Newey was now acting like a sounding board, with the team bouncing ideas off him, Wache confirmed: "It’s for sure. And after, he’s challenging us. I tell you I would say more challenging than [agreeing].
"I think it’s good. Because when you have a step back, you see also different things. He has a different background than all of us. And also, he has some knowledge that we don’t have. Because we didn’t experience that [yet]."
On top of Newey's experience, the Frenchman is particularly impressed with his humility, emphasising that he creates a healthy working environment: "He’s a very smart person and he’s still very open-minded. People with plenty of success normally [think] their idea is the best, and he’s not like that. He’s very open-minded. I think he’s working like that – as a mentor and challenging us."
Additional reporting by Ronald Vording
