Formula 1 vs Le Mans: why GP racing is still the pinnacle

“The biggest difference in driving the two cars is that in LMP1 we had four-wheel-drive [through the hybrid system], while in F1 we have close to 1000bhp all going through the rear axle of a car that weighs less than 800kg. Those are impressive numbers and a lot to manage through your right foot.”

Le Mans 2018: Alonso, Buemi and Nakajima score victory for Toyota

That’s why, in terms of driving experience, Hartley believes a Le Mans prototype is no match for an F1 car. “The 919 Hybrid had huge acceleration due to the four-wheel drive: the initial thrust out of corners was incredible. But a modern Formula 1 car, no question, is the quickest race car in the world,” he says.

“I first drove it in Austin last year, and thinking about it now still blows my mind. The first sector of that track [the Circuit of the Americas] features a sequence of fast, flowing corners. I’ll never forget the first time going through that sector, my neck wanting to be ripped out from left to right. That’s something no other racing category has: that pure performance in high-speed corners.

“When you see an F1 car on track at high-speed, it’s mind-blowingly fast. As a driver, you get used to it, but when you take a step back and reflect, it’s amazingly impressive, the speeds and forces we’re put under lap after lap.”

Opinion: why the time is right for hypercars to take over at Le Mans

Both Le Mans prototypes and F1 cars feature extensive use of hybrid powertrains, which in turn means both types of car feature a great emphasis on efficiency. Hartley says this is a development of modern racing cars that's often overlooked.

“Modern F1 cars aren’t just the quickest we’ve ever seen, but they use half the fuel they did 15 years ago,” he said. “It’s something we don’t talk about often, but the efficiency of F1 and Le Mans cars is something I’m proud to be part of, both working with Honda now and in my past life with Porsche. We’re developing technology at the highest level that you can pass onto road cars.”

Tyres: built to last vs part of the show

A key to success in endurance racing is spending as little time in the pits as possible, so maximising the life of tyres is a key factor. That’s a major contrast to modern F1, where Pirelli deliberately produces rubber designed to degrade to promote different strategies and mix up the racing.

“As the only part of the car touching the ground, tyres are a very big part of the puzzle,” says Hartley. “We used Michelin in sports cars and use Pirelli in F1, and they’re different sizes and compounds.

“The Pirelli F1 tyre is quite sensitive, so we talk a lot about tyres for qualifying and the race in terms of degradation. Getting the most out of an F1 tyre is very complicated, so we’ll have long meetings – hours on end – just on tyres.”

The mental challenge: why F1 drivers must be selfish

Another major adjustment Hartley has faced in switching is in the style of racing. Clearly, endurance events last significantly longer than F1 races, but Hartley says the biggest changes surround not sharing a car with team-mates.

“In endurance racing, I was part of a team of drivers. Even coming to a decision on set-up was very much a team thing. I learn a lot from that, but it’s different in F1: you have to be a little more selfish, think of yourself more. The pressure is all on an individual, rather than spread over three drivers.

“I’m still a team player, but in F1 your time becomes quite precious. The environment is mentally draining: there’s a huge amount of pressure, and I’ve realised I have to find time to think a little for myself. I don’t like the word selfish, but in F1 you have to think about focusing your energy on areas that bring performance.”

That said, Hartley is quick to note that his endurance racing career carried its own expectations. “Representing Porsche at Le Mans comes along with a lot of pressure, and that wasn’t always easy,” he says. “I was lucky enough to have team-mates such as Mark Webber, and I really learned from them about how to deal with pressure.”