Honda partnership "a release" for Toro Rosso

Red Bull's junior team will have a works engine partnership for the first time next season, having ceased its Renault customer status in order to take over McLaren's vacated Honda supply.

Key, who worked at Force India and Sauber before joining Toro Rosso, said it was a big moment for the team.

"It feels very exciting," Key told Motorsport.com. "Like a release really, because it's the sort of thing that you always want to do to make the next step with your team, and it hasn't been possible until now.

"It's a huge challenge, and it's also a huge responsibility to that company as well. It's nice to have a partner rather than a supplier.

"You can really talk about the whole project and work out what the globally best solutions can be."

During McLaren-Honda's tumultuous reunion, the quality of communication between the British team and the Japanese manufacturer was often under scrutiny.

"I have to say that the communication flow has been really good, they are incredibly quick at being able to respond to requests and questions," said Key.

"They seem to have a lot of information available, either to hand, or they're able to find out pretty quickly if you need a particular bit of data.

"We've had a lot of technical discussions, and they have supported it and communicated it very well."

Toro Rosso's Honda deal has come together after the team started work on its 2018 chassis, but Key reckons it is much better than when it picked up a year-old Ferrari supply deal late in 2015.

"We've built up a resilience and flexibility in the team to having to cope with late decisions or changes of direction, which sometimes you might expect and other times you may not," he added.

"Because we've been through it on a number of occasions before, we're very proactive with our planning, and put as much forethought into something as possible.

"If it looks like something might happen, we start immediately talking in the background about 'What if?' scenarios.

"It's several months earlier than the Ferrari situation in 2015. It's quite a bit easier to deal with, although there's a lot of work to do."

Honda made it clear it felt the split from McLaren was in the best interests of both parties, and McLaren co-owner Mansour Ojjeh said he is "happy" it has found another team to supply in the form of Toro Rosso.

"It's like irreconcilable differences in a marriage or something," he said. "They've done as much as they could. And we've done as much as we could, and it didn't work."