Hartley, like many of his contemporaries, has been racing competitively for over a decade.
Therefore, his age on paper belies the number of race kilometres he's covered both on the tarmac and in a simulator, which in this day and age is the foremost tool for aspiring young drivers.
"I still have to pinch myself sometimes to make sure I'm actually a Porsche factory driver," said Hartley.
"It's been something I've been working towards since I started racing in endurance cars and to be able to go testing at Paul Ricard in the new Porsche 919 Hybrid car last weekend was something really special.
"We didn't expect to be so quick so early on, especially with a new car. The main goal at the moment is to get the car to be reliable and topping the time sheets came as a bonus. We actually did an endurance test at the beginning of the week and managed to get two full six-hour race simulations completed."
Last weekend was the first time the Porsche factory has run two of their new hybrid cars together at the same time. There were upwards of 100 staff making sure the very complicated 919 ran as smoothly as possible.
It's a big project and each time the cars are wheeled out of the pit garage the drivers, engineers, mechanics and everyone else involved learn something new. Getting a lot of track time in the cars is a confidence builder for everyone involved in the project.
"Every time we get in the car we're moving forward and making progress. The car is unbelievably complicated but very satisfying to drive. At Paul Ricard we had a top speed of 340km/h so it's quick.
"The car is four-wheel-drive and the regenerative electric motors on the front wheels provide massive acceleration when they kick in. It's a very special, unique car and very different to anything else I've ever driven.
"One thing hasn't changed though, we're on the limit pushing the car as hard and fast as we can. It is interesting that we're using technology that one day will end up on road cars so that's kind of cool," said Hartley.
Hartley is paired with two experienced endurance drivers and as the junior member of the triumvirate is keen to learn as much as he can from the others.
Endurance is different from most other forms of motorsport, where your goal is to beat your teammate, whereas in this form of racing the idea is to bond with your teammates to achieve the common goal of winning together.
"If I can just learn a few small things off both of them I'll be okay. We all learned a lot during the test and are starting to work well together. Our competitors will be hard to beat, but our first goal at Silverstone is to finish the race and build the reliability for Le Mans. Anything on top of that will be a bonus." said Hartley.
The Kiwi's first race in the eight-race championship is in the Six Hours of Silverstone, April 20.
WEC 2014 championship
6 Hours of Silverstone - April 20
6 Hours of Spa Francorchamps - May 3
24 Hours of Le Mans - June 14-15
6 Hours of the COTA - September 20
6 Hours of Fuji - October 12
6 Hours of Shanghai - November 2
6 Hours of Bahrain - November 15
6 Hours of Sao Paulo - November 30
