Kimi Raikkonen has admitted that he retired from F1 not feeling as fast as he did in the early part of his career, but couldn’t quite put his finger on what exactly had changed over those 20 years.

Walking away from F1 after two decades in the sport, Raikkonen was once regarded as the fastest man in the sport in the mid-2000s, but felt he lost his raw pace as time went by.

“Obviously, I was a lot younger than I am now,” he said on the F1 Nation podcast.

“20 years makes a difference in you, for sure. I’m not as fast as I was when I was 25.”

Asked whether he could identify what it was that made him think that, Raikkonen said it came down to a feeling rather than anything specific.

“I don’t know,” he admitted.

“I don’t feel it, but I’m sure something happens. It’s impossible that nothing happens, then there are obviously other reasons because every year [is a] different car, different tyres, this and that.

“In some years in those days [2005-2007], they could fit you a bit better at the beginning or later on in the season.”

Change of tyre manufacturer

One hypothesis is that Raikkonen simply didn’t adjust to the Bridgestone tyres once they became the sole tyre supplier in 2007, after racing on Michelins with McLaren.

But it’s not a theory that Raikkonen puts much stock in.

“I don’t think it’s as simple [as that],” he said.

“I think the tyres, for sure, had a lot to do [with it], obviously the cars are different between the teams and this and that.

“But I think, in 2007, everybody had the same tyres. What happens then obviously, they don’t push as much. It doesn’t matter, the manufacturer, that much. You give everybody the same and deal with it. Even the year before, I’m sure the Bridgestones were very good when it was still a war between Michelin and Bridgestone.

“I don’t think there was such a big difference between Michelin and Bridgestone when they were really fighting against each other than there was [with] one and giving it to everybody.”

When was peak Kimi?

Asked whether he felt he was at his absolute best in the 2005-2007 period as he claimed the ’07 title with Ferrari after his strong 2005 and 2006 seasons, Raikkonen said there were peaks and troughs through the years.

“I was doing well in 2003,” he commented.

“Obviously, our car was probably not as quick as we would have made it. But [in] 2007, I don’t think we did too badly. Otherwise, we wouldn’t have won the championship!

“It took a while to get used to it [the Ferrari]. Especially the latter part of the year, we were very, very fast, especially in the race conditions.”