Mark Webber has predicted an early retirement for his former teammate Sebastian Vettel.

Throughout German Vettel's four-year championship-winning reign, Australian Webber was his teammate at Red Bull, where in 2010 they initially tussled for the first title.

"Obviously the scorecards aren't exactly in my favour," Webber, who retired from F1 after 2013 and will now spearhead Porsche's prototype return at Le Mans, told the March edition of Motor Sport magazine.

"Especially since we went to the Pirellis," Australian Webber, 37, told journalist Nigel Roebuck. "He destroyed me on those, but I can live with that."

That's because over a single lap, Webber thinks even his famous Ferrari ally Fernando Alonso struggles to match Vettel.

"I always thought Fernando was the best, and I still do -- on Sundays," he said.

"On one lap, though, I think Seb's got him covered -- and I'm taking in terms of preparation, not just pace.

"Seb's strengths, as we know, are escaping at the start, and running in clean air -- he's like a computer, isn't he? His only weakness was always fast corners."

When it comes to slow corners, however, Webber admits Vettel is untouchably strong.

"A couple of weeks ago I watched the Singapore race on television for the first time: he was two and a half seconds quicker than anyone, and he had Nico, Fernando, Lewis and me behind him," he marvelled.

"It wasn't as though he was racing a bunch of muppets! Ok, it wasn't always like that, but at some races he was exceptional."

Also unique, Webber admitted, is Vettel's approach to life so far.

Although Vettel is notoriously private, Webber thinks his former rival has positively sped through his 26 years of life so far.

"Do you know what?" Webber said, "I think Seb will do everything early in life.

"He's got his championship titles and his results early, he's going to have a kid early and I think he'll retire early -- he'll probably take a blast in the red car, then sayonara."