It was actually my own car, " he says. I'm a total gear head." Nor did he need a stunt double to deep sea dive in shark waters off the Bahamas in Into The Blue. I grew up surfing, " he says. Even the huskies he drives through sub zero Antarctic blizzards in Eight Below seem to sense that he's not faking. I've a bunch of dogs at home, " he says.

Like the classic Hollywood male stars of the 1950s, the 6ft 3in Walker is his own man, a loner who keeps his cool and does the right thing. Paul reminds me of Steve McQueen, " says Frank Marshall, producer of the Indiana Jones movies, who cast him in Eight Below.

McQueen really rode that motorcycle in The Great Escape. He drove the car in Le Mans. Like McQueen, Paul feels right doing these things. I wanted Eight Below to feel real."

The 33-year-old Walker grew up in the Californian outdoors, a Marlboro Man without the cigarettes. He's a grandson of the boxer 'Irish' Billy Walker. ?He was one of my idols because he also raced cars. He was a phenomenal mechanic. He had the best transmission shop in the San Fernando Valley.

You could bring in anything and he could fix it. He commanded a tank battalion under General Patton when he was 17 years old, come up through Sicily. He went on to serve in Army Intelligence in the Korean War. He went around with a cyanide capsule embedded in his molar. That's the kind of guy we're talking about. I think this whole career of being an actor plays into what he taught me."

Billy Walker fought twice for the middleweight championship of the world. I've seen footage of him fighting. I have pictures of him all bashed up. He was a tough guy. He encouraged me and my two brothers to wallop each other but always give a big hug afterwards. I grew up with both a speed bag and a heavy bag in my back yard. We were always putting together combinations and working on foot work and head movements."

Walker trained in martial arts as a small kid.

Bruce Lee used come around. My grandad admired him. I still box, but more Thai boxing now, with elbows and knees."

The family didn't have much money. Walker's mother had been a model and got them work in commercials as children. It wasn't something she necessarily wanted for us but she knew there wouldn't be enough money there otherwise for us to go to college. Mom always had a camper in which she would take us up the mountains. She got us involved in the Young Rangers programme in the national parks. As I grew older my father was more concerned with the boys playing sport, so naturally that's what we did and we didn't do nearly as many commercials. The whole acting thing didn't come back until after I majored in marine biology."

He made his acting debut opposite Reese Witherspoon and Tobey Maguire as the high school athlete in the Gary Ross time-warp comedy Pleasantville. Having impressed in The Fast and the Furious as the undercover cop stripped of his badge but given a chance to redeem himself by infiltrating gangs of street racers, he took over the lead role when Vin Diesel refused to sign for the sequel 2 Fast 2 Furious. I felt let down, " he says. I thought we were partners. I see making movies as a team sport, right You need to know you can rely on everyone. The second you have one person looking out for themselves, that's a weak team. The star players can't act like star players. It's important to remain humble even if the guy next to you may be just a bench warmer. Without the bench warmer you're not going to make it to the finals."

That's what he liked about Eight Below.

Frank Marshall brought the entire cast and crew high up the British Columbia mountains and to the glacial wastelands of Greenland which resembled the frozen wilds of Antarctica, where Walker's character is required to rescue a team of huskies left behind for months after an expedition had to be aborted. You want to see the real adventure, " Walker says. It has to be a real test of endurance. I was an athlete before I was an actor. That plugs in with the moviemaking."

Although Walker slips easily into the persona of a homespun all-American hero, he's wary of people trying to categorize him. I like dark movies, " says Paul Walker. I think dark is closer to who I am." He outraged American conservative family activist groups with Running Scared, a thriller about two 10-year-old boys who get their hands on a mob gun used in the shooting of a cop. Walker plays the father of one of the boys who has to locate the kids before the mob finds them first. After its release in February, New Line Studios gave in to pressure and pulled a racy online game promoting the movie because of its explicit sexual scenes and frequent use of the f-word.

I thought with Eight Below I'd baptise myself in the name of Disney and possibly be forgiven for all my sins, " he jokes. Eight Below was shot around the time Into The Blue opened.

Someone in Disney thought I looked decent with my shirt off so they even managed to contrive a scene in which I had to race through the snow half naked. I suppose it was a kind of redemption."

Running Scared is a second movie by Wayne Kramer, who directed the terrific William H Macy film noir The Cooler. Wayne's the real deal, " says Walker. The Weinstein brothers are going to carry his latest project, Evil Seek.

He's got an insane mind. Anyone from outside looking in would assume he's just got to be the most twisted individual, whereas the truth of the matter is he's like a real loving father and a great husband."

Walker can be defined by who and what he admires. He's a big fan of Jeff Daniels, who played the ice cream parlour owner in Pleasantville and is currently starring in The Squid and the Whale. He doesn't buy into the whole Hollywood machine. He comes in and does a really good job, but immediately afterwards he disappears. He goes back to his family in the midwest. He understands that the whole Hollywood game is not going to make him better at his craft. He's got a real blue collar approach to acting. I think it's unfortunate we don't see more of him."

Raiders of the Lost Ark is one of his favourite movies. Indiana Jones is not a superman, he's just this ordinary guy being inventive and finding a way out of situations. Everything he does is believable. When that big ball rolls after him, it's really happening. It's not a digital trick."

Last year, Walker filmed the action drama The Death and Life of Bobby Z, playing an exmarine who helps out drug enforcement agent Laurence Fishburne by impersonating a recently deceased drug-lord, and ends up on the run from the law. We'll see what happens with it, " he says. It's a concern right now. I'm hoping there's a way to salvage it. John Herzfeld, who directed Two Days In The Valley, came in with just three weeks of prep. We had another director attached but his focus was questionable. He just didn't seem to be there.

There was just a very small window where Laurence's schedule was clear. So we were under the gun. It was an opportunity to experiment.

My younger brother plays my character when he's younger. My other brother is the film loader. My best friend is the stunt coordinator.

I just hope we can pull the loose ends together."

Walker will next be seen in Flags of Our Fathers, Clint Eastwood's Pacific War epic dealing with the infamous battle for Iwo Jima.

?I told the casting director I didn't care what role I got. I'd scrub floors just to be in it. I finally convinced her."

Flags of Our Fathers is a break from Eastwood's more intimate movies Mystic River and Million Dollar Baby. I think Clint's biggest battle is with the aura of greatness that just follows him everywhere. People see an iconic figure. He's doing the best he can to strip that away and make himself approachable. He's real unassuming. The thing I really like about him is the consistency in the way he deals with people. It doesn't matter where you are in the social ladder. You could be a valet parking cars or you could be Steven Spielberg, he's going to treat you the same. When I was finished with my scenes he made me feel that he would have liked to have had more of me in the movie."

'Eight Below' opened nationwide on Friday.

'Flags of Our Fathers' is due for release this autumn.