How serious is Sir Chris Hoy?

It's all too easy to take a glance at Sir Chris Hoy's motor racing career and see it purely as a PR stunt.

All the signs are there. One of the world's largest car manufacturers - Nissan - has successfully rebranded Hoy into a racing driver, through campaigns in British GT and the European Le Mans Series, all with the Japanese firm's logo hanging proudly over him. Marketing genius some would say.

Next up. His biggest challenge yet - the Le Mans 24 Hours. He's due to race in the LMP2 class alongside Michael Munemann and Parth Ghorpade in the Algarve Pro Racing Ligier JS P2-Nissan.

The headlines have already been written, and the sceptics have multiplied along with the rise in the level of public interest whenever Le Mans is mentioned.

But before you write Hoy's racing exploits off as nothing more than a marketing exercise designed to feed off his legendary cycling success, know one thing. Sir Chris Hoy is a racing driver now, and a very capable one at that.

Like it or not, motorsport is, and always has been, a strong passion for the 40-year-old Scot. It is something he would have indulged in far earlier had it not been for the persistent demands of his Olympic and world championship cycling career. Spend five minutes in Hoy's company, and you quickly realise how down to earth he is. And most of all how proud he is to be living his childhood dream.

"I'm acutely aware of how lucky I am to be given these chances," says Hoy earnestly.

"The general media can see it as a PR stunt and say 'yeah we'll make a big thing of it now, but there will probably be an excuse somewhere down the line and he'll never actually do it'. In my mind there has never been a chance that I wouldn't do this because I want it so badly.

"I've always loved motorsports. When I was six I got a Scalextric kit and I remember asking my dad why one of the cars had lights on it. He said it was because it was a Le Mans car and it had to race through the night. From that moment on I've been aware of and followed Le Mans. It's the greatest race in the world and it feels surreal that I'll be on the grid with the best drivers and teams in the world in just a few weeks."

Hoy's LMP2 debut yielded a 10^th place finish in the ELMS season-opener at Silverstone recently. Next up is Imola on May 15, before the big one in France.

Hoy isn't a stranger to racing prototypes. He began his career in Radical's baby SR1 in 2013, before lifting the inaugural LMP3 title last year alongside Charlie Robertson in a Ginetta-Nissan. His graduation was punctuated by a year in GT3 racing with a Nissan GT-R NISMO with the works RJN team in British GT.

Hoy says he feels more at home in prototype competition than in the heavier GT3 cars.

"I find the prototype much more intuitive to drive," he explains. "The GT cars were quite unpredictable for me, purely as it's a different style of driving. I'd gone from this little 500kg Radical to a 1300kg GT-R. I was smashing the brakes and waiting for the ABS to do its thing before getting going again and I found it quite difficult to read what the car was doing.

"With the prototypes it's real fingertip stuff. It's very physical but the car communicates what's going on to you better. Maybe it's because I started in Radicals, which have little downforce and move about a lot, like a go-kart. But when you drive the LMP2, correctly, it does what you want it to and you feel more connected to it on the limit."

Of course being a multiple world and Olympic champion has its benefits. And Hoy says that he can draw many bonuses from his experience of cycling at the highest level.

"There are advantages from my cycling experience that some drivers may not benefit from," he explains. "Simple things, like mental preparation.

"The biggest thing is being able to focus on the things you can control and block out the stuff you can't. For example you can't barrel into a corner at Le Mans, find your reference point and then think 'hang on there's a bloody great wall over there, what if I get this wrong, what if a wheel falls off right now?' You have the simplify things and worry only about what you control.

"We all get nervous and have doubts at times. I had the exact same feelings before I raced bikes, that mixture of nerves, adrenaline, anticipation and often doubt. But you learn not to dwell on them or engage with them and not let them affect your performance. In a way that feeling is nice, because I never thought I'd experience it again after I retired from cycling."

The physicality and skill involved with motor racing also didn't take Hoy by surprise. He knew he'd have to work hard to get to a frontrunning level in everything he's raced.

"It's like people saying 'well I can ride a bike, so I can win Olympic gold medals'. Theoretically you can, but it takes a hell of a lot of work and constant training a commitment and motorsport is exactly the same.

"It can look easy from the outside but when you try for yourself you realise the skill that's required and how easy some of the professional guys make it look. I've had times when I was convinced I was flat-out, absolutely on the limit, nailing the lap. Then I come in and the Pro driver goes out and knocks a second off your time.

"It's amazing and it's a constant learning exercise. It's a hard sport, and only through hard work and learning can you get on top of it."

Regardless of where his racing career takes him, Hoy is adamant that motorsport will never be a direct replacement for cycling. Hoy has other commitments now, such as his own bicycle brand, a range of children's books, and he also actively mentors the next generation of Team GB athletes.

"Motorsport isn't a replacement for cycling because I can't do it seven days a week," he says. "Cycling used to be all I did, all day every day, motorsport can't be that. It is a big part of my life, but it's not everything in my life. When I put my helmet on it is everything for those moments, but when I'm not in the car I have other concerns and commitments.

"One of the joys of motorsport is the fact that I got to become a rookie again. I went from being at the very top of a sport, and when you're there the scope for improvement is so marginal - we're talking finding 0.050s over a four year gap between Olympics. But when you go into something totally new the improvements are much easier to find and you see genuine progress with every session. That's been one of the most gratifying aspects for me."

The pressure on drivers at Le Mans is possibly larger than at any race in the world, but Hoy will also have to handle the heat of the media spotlight over the week in La Sarthe too. Hoy is used to pressure, but he says his biggest worry is being able to perform to the level the chance demands.

"There is pressure of course but to be honest it comes from me, not from what anybody else says or writes," he says. "I only feel the pressure of having to do a good job. I don't want to be gifted a seat purely because I used to be a cyclist that won some shiny medals. I want to go in and treat it with the respect it deserves and give 100 per cent commitment, much like I did in cycling, and much like any aspiring driver would do in the same situation."

Hoy already has experience at Le Mans, having done last year's test day in his LMP3 car alongside Robertson.

"The car wasn't much faster than the GT cars and a lot slower than the LMP2s, so you drove in the mirrors a lot and it was quite daunting as the sheer speed and grip of the LMP1s coming past you is insane. They're on a different planet. With the LMP2 you're more in the mix and can look forwards more.

"Handling traffic will be crucial. It's about understanding the principles and being very clear what you're doing. If there's a P1 car behind you, you stick to your line until it's past you. Or if you're going for a corner you have to commit and go for it and be very clear with your intentions on-track.

"There's undoubtedly a lot of work to do between now and Le Mans, but I wouldn't be doing it if I didn't feel ready for it."