Mercedes rivals handed stark warning after Kimi Antonelli issues high praise

Kimi Antonelli has handed Mercedes' rivals an early warning after praising the initial performance of the Silver Arrows' power unit.

The 19-year-old was the first driver to exit the pit lane at the start of the opening day of the official shakedown test in Barcelona, before handing the W17 over to George Russell.

In cold conditions, Antonelli completed 55 laps, the best of which was a 1m 20.700. He very much enjoyed being back behind the wheel and gaining an understanding of F1's new power unit regulations.

"Yeah, it was a very interesting morning—very nice to be back in the car, of course," Antonelli told F1TV. "It's a massive learning experience.

"We've been trying to tune the power unit and the car. Obviously, this afternoon the car has improved a lot. 

"It's a constant learning process, so the most important thing is trying to get as much running as possible, in order to tune the power unit and the car in the best way possible."

Heading into the new regulations, Mercedes is very much considered the early favourite, given how dominant it was when the turbo-hybrid engines were introduced back in 2014.

The opening day in Barcelona painted a very positive picture for the Brackley-based team, with George Russell completing an additional 93 laps in the afternoon.

Speaking specifically about the performance of Mercedes' engine, Antonelli praised the Silver Arrows for the job they have done, adding that the car already feels good.

"I have to say the team has done a really good job on the power unit side," added Antonelli. "Drivability, which was a big question mark, seems to be good so far.

"So obviously, it's early days, and that's why, with the running, we will discover a lot more about the car and the power unit. We'll be able to see where it's lacking and where it's actually good. But so far, the package is feeling good."