The commitment and determination that characterised Webber's career behind the wheel will transfer into new or expanded off-track roles at races, an international business venture, the revival of his charitable adventure trek and competing in mountain bike races.

He will regularly attend F1 races around the world in his continuing role as a Red Bull ambassador and expert analyst on Channel 4 TV's telecasts in the UK, and be a frequent visitor to sports car endurance classics like the Le Mans 24 Hours in his new position as a Porsche representative.

It says a lot about Webber that his two most recent racing employers have retained him on long-term agreements to represent them globally.

He is only the second ex-racer appointed by Porsche as a special envoy, joining German rally legend Walter Rohrl.

Webber, 40, drove his last race in Bahrain last month, finishing third in his final appearance with the Porsche team that he helped guide to supremacy in sports car racing over the past three years.

It was an emotional farewell for the popular, straight-shooting Australian who defied the odds by rising from an unprivileged background in Queanbeyan, near Canberra, to become an F1 star.

Glowing tributes from around the world, both from within motor sport and the wider sporting community, underlined the respect Webber has earned in his career.

In 12 seasons in F1, which began with a stirring fifth place in his debut with underdog Minardi at the 2002 Australian Grand Prix at Albert Park, he survived a string of uncompetitive cars to finally prosper with Red Bull Racing.

Webber and the team hit their stride in 2009 and, amid internal favouritism to Sebastian Vettel, he kept the gifted German honest during their five fractious seasons as teammates.

He won nine F1 races and seriously contended for the 2010 world title before quitting F1 at the end of 2013 to lead Porsche's return to Le Mans-style international sports car racing.

In his three seasons of long distance racing with co-drivers with Porsche, Webber won several times and played a crucial part in developing the 919 Hybrid racer into the dominant machine in 2015 and again this year with back-to-back victories in the Le Mans 24 Hours classic and the world endurance championship.

Le Mans glory eluded him, but he claimed the sports car world drivers' championship last year with his co-drivers, Germany's Timo Bernhard and New Zealander Brendon Hartley.

Surprisingly, it was the first and only championship title of Webber's 26-year career.

His decision to retire was typically straightforward, amounting to the realisation around the middle of the year that the commitment and determination that had driven him for so long was waning.

"It's been a long old career," Webber said. "It feels like it, too. I've had a pretty good run, but priorities have now changed. I don't have the fire and the batteries are a bit lower, and priorities in your life change.

"I've been doing it long enough and I'm ready for a change. I've worked pretty hard and I just want to make sure I get a good chance to enjoy that and also not find out where that little slope is where you're not quite doing what you should be doing.

"I'm leaving at a good time."

Webber acknowledges that, having escaped three aerial accidents and other heavy crashes, he is walking away from racing without serious injury.

"It's a numbers game," he said. "I've had some close shaves. I will totally look back and say, 'You know what? I'm in good order'. I don't trivialise that at all.

"Not everybody's had that good fortune. It became something I thought about in my late 30s."

Webber's worst wound was a badly broken right leg suffered in a collision with a car while he was cycling in a remote region of Tasmania during his Mark Webber Challenge charity event in November 2008.

He is still a cycling enthusiast and plans to compete in mountain bike events to keep up his renowned fitness and help fill the competitive void.

He admitted that not racing any more will be a difficult transition, but it is a change for which he is confident he is mentally prepared.

"Of course, there are parts of it I'll miss, totally," he said. "How are you going to replace all that stuff? You can't - and that's fine. Get over it. Life goes on.

"You can't be 22 forever. You have to slowly ween yourself off that drug, which is the competition, which is brilliant. I love it. So I have to find different things in the future to replace that buzz.

"That's the next challenge of any sportsman's or sportswoman's life (after retirement)." In addition to his ambassadorial and TV duties, Webber is preparing to start a new Australian-based, international business next year that he vaguely describes as being "involved around my sporting background".

He added: "It's a pretty ambitious goal, but I'm going to try to give that a go. So chapter two." He was more forthcoming on his plan to bring back the Mark Webber Challenge in 2018, weighing interest from several states to host the arduous multi-day event, which tests elite athletes and fit amateurs over difficult kayaking, cycling and walking courses to raise money for charities.

Run on and off from 2003-13, Webber is hoping to bring the challenge back as a true test of physical and mental endurance.

"There's a lot of interest," he said. "We were probably before our time with that sort of event. In terms of health and safety it was on the edge, but it was a real challenge. And that's what we need.

"We need to cut back the red tape and have people putting it on the line for an event like that. You can't pretend with an event like that. You have to start preparing six months out."

Although he will remain based in England at his property north-west of London, Webber will spend more time in Australia visiting family and friends.