Martin Brundle left stunned after Red Bull tour: 'My God, this is unbelievable!'

Martin Brundle has been left far from surprised by what he has seen so far from Red Bull Powertrains' debut in F1 given what he saw when on a tour of its facilities by former team boss Christian Horner.

Heading into the upcoming season, there was a question mark over Red Bull and its new Powertrains department, bearing in mind it has constructed its own power unit for the first time in its 20-year history.

After the first four days of testing at Barcelona's Circuit de Catalunya, however, Red Bull and Racing Bulls had combined for just over 500 laps, at least ticking a box on reliability and providing a platform on which to build.

To many, that has come as a surprise, yet for former F1 driver and Sky Sports co-commentator Brundle, that has been far from the case.

"They've done really well, haven't they?" he said, speaking on Sky Sports F1. "I remember Christian Horner took me around the engine factory more than one and a half years ago, and I thought, 'My God, this is unbelievable!'

"The scale of it, the number of people and the facilities and the dynos they had there, so I'm not that surprised, if I'm honest. I know they're new to Formula 1 power units, but they've a lot of good people there, a lot of resource and it's a great facility."

Oh so different to 2014

Brundle feels Mercedes has "the upper hand at the moment" after running for 500 laps in its own right over its allowed three days of testing, and will have an advantage in supplying three other teams - McLaren, Alpine and Williams, although the latter has been absent this week.

With the two teams providing data, Red Bull Powertrains also has an edge over the likes of Aston Martin and Audi.

"Ferrari looks pretty solid as well," he said. "I think the teams that have the biggest challenge, for example, Aston Martin with Honda, because there's only one of them, and Audi. There's only one of them.

"At least Red Bull has the two teams with the power unit, and Mercedes will eventually have four teams charging round, so their learning capacity, their rate of gain will be higher, I believe. So that bodes very well for those four teams eventually."

Generally, Brundle expressed "relief" at what he had seen overall, comparing it to what happened 12 years ago when F1 introduced the new hybrid system PUs.

"Given it's clearly the biggest change in the history of Formula 1, with the power unit and the chassis, with the active aero, we were expecting gremlins and problems," he said.

"I guess we all remember 2014 when the new hybrid engines came in and the cars weren't getting out on track, and if they did, they broke down straight away.

"It just reminds you of the level of investment in Formula 1, the quality of the people and the facilities, that they could just rock up and start charging around the racetrack, because the cars are so complex now.

" I am very impressed by how the teams have largely got their acts together and just got on with it."