Less than two years after winning the 2024 Porsche Carrera Cup North America championship with Kellymoss and one year after claiming the Porsche Cup, Loek Hartog is preparing for the next major step in his career.
It was announced today that the former Porsche Motorsport North America Selected Driver and current leader in the 2026 Porsche Cup standings will make his IMSA WeatherTech SportsCar Championship GTD Pro debut at Watkins Glen International, sharing the iconic Manthey Racing ‘Grello’ Porsche 911 GT3 R with Porsche factory drivers Klaus Bachler and Michael Christensen.
For Hartog, the opportunity is the latest milestone in a career that has continued to gain momentum since arriving in North America.
After arriving in the United States as a Porsche Mobil 1 Supercup race winner, the Dutchman dominated the 2024 Carrera Cup North America season with Kellymoss, winning seven of 16 races and finishing off the podium just twice on his way to the championship.
His success extended well beyond North America. Hartog’s performances across Porsche’s global customer racing ladder earned him the 2025 Porsche Cup, awarded annually to the world’s most successful private Porsche racing driver.
By stepping into the iconic “Grello,” Hartog follows in the footsteps of some of the most decorated drivers ever to race a Porsche including Bachler, Christensen, Timo Bernhard, Nick Tandy, Romain Dumas, Earl Bamber, Kévin Estre, Laurens Vanthoor, Matt Campbell, Mathieu Jaminet, Richard Lietz, Frédéric Makowiecki, Marcel Fässler, Patrick Pilet, Lucas Luhr, Thomas Preining and Ayhancan Güven, a group whose achievements include FIA World Endurance Championship titles, DTM championships and victories in some of the world’s biggest races, including the 24 Hours of Le Mans, Nürburgring 24 Hours and Rolex 24 At Daytona.
“It’s probably the most excited I’ve ever been,” Hartog said. “I’ve done some of the greatest races over the years, but this is for sure the biggest opportunity or biggest step. It’s GTD Pro. It’s the best GT3 drivers in the world, and to be recognized for that, it’s something special.”
While the opportunity may represent a career milestone, Hartog arrives at Watkins Glen with considerably more experience than his IMSA debut designation might suggest.
Since winning Porsche Carrera Cup North America in 2024, Hartog has raced across Europe, Asia, and North America. Last year, he competed in the 24 Hours of Le Mans, Nürburgring 24 Hours, and CrowdStrike 24 Hours of Spa on three consecutive weekends. This year, his programs include a GT World Challenge America campaign with Kellymoss alongside John Gilliland.
That breadth of experience is one reason Hartog believes he is ready for the challenge.
“Ever since leaving Carrera Cup, I’ve been doing some of the greatest races,” Hartog said. “To get this opportunity now feels like a natural next step. It’s obviously very cool to be recognized, but I don’t feel extra pressure because of it.”
“I’ve done so many weekends now in Pro-Am racing. I’ve had time to sharpen my tools. In essence, it’s not something completely different. It’s just very cool to be in this environment and to have this opportunity.”
The road to Watkins Glen began long before his championship-winning season with Kellymoss.
Before moving to North America, Hartog spent three seasons competing in Porsche Mobil 1 Supercup, Porsche’s premier international one-make championship. Racing on Formula 1 weekends, he earned a victory at Zandvoort in 2023 and established himself as one of Europe’s leading Porsche racers before joining the North American ranks in 2024.
Yet despite his success in Europe, he felt a move to North America would ultimately provide greater opportunities.
“Making the step to the U.S. was one of the most important decisions I’ve made in my career,” Hartog said. “I felt like I was at a very good level in Europe, but like in life, if you want to make a difference, sometimes you need to make bold decisions.”
“I felt like making that step to the U.S. was my calling. Looking back now, it was actually one of the biggest things I’ve done. It was really pivotal.”
The move also broadened his perspective on professional racing.
North American racing exposed Hartog to a broader side of the sport that extended beyond pure performance.
“It taught me about opportunities, relationships, and all the different elements that go into building a racing career. It gave me tools that I didn’t have before.”
Hartog credits Kellymoss with helping accelerate that development, beginning with his championship-winning Carrera Cup campaign in 2024.
“I’m very sure that making my mark in the U.S. with Kellymoss helped me make this step into IMSA,” Hartog said.
“But it is more than just the on-track success; being part of the Kellymoss “family” has taught me so much more about all aspects of our sport. I’m incredibly grateful for everything that Andy (Kilcoyne) and Victoria (Thomas) have done for me.”
For the Dutchman, the significance of the opportunity extends beyond the race itself.
“When the opportunity came up, it was one of the biggest moments I’ve ever had,” Hartog said.
“Next to being a racing driver, I’m also a big racing fan. I’ve been following this car for my whole life.”
“When I was a little kid going to the Nürburgring with my dad, this car was already racing. The coolest thing is that my heroes and my dad’s heroes raced that car. Now, to step into that role myself is a completely different perspective.”
“I still get goosebumps thinking about it.”
The outing also comes during Manthey’s first season competing in the United States, with the German team contesting the IMSA Michelin Endurance Cup for the first time. Manthey has made an immediate impact in North America, winning the Mobil 1 Twelve Hours of Sebring with its iconic No. 911 ‘Grello’ Porsche 911 GT3 R in just its second IMSA start.
Sharing the car with Bachler provides Hartog with a teammate he already knows and trusts – the duo drove together at Le Mans last year and were teammates in a Manthey Asian Le Mans Series entry with Antares Au.
“He’s one of the most rounded teammates I’ve witnessed. He’s incredibly calm and sees the bigger picture.”
“He’s the perfect teammate to share a weekend like this with.”
For Hartog, the Watkins Glen debut represents another step in a journey that has accelerated rapidly since arriving in North America.
What began as a decision to leave Europe has led to championships, major endurance racing opportunities and now a place on one of North America’s biggest sports car racing stages.
It is also validation that the path he chose was the right one.
“When I stepped off the plane in America, one of my biggest wishes was to understand racing better and understand where I fit into this industry,” Hartog said.
“Now, two and a half years later, I feel like I understand that much more clearly.”
For a driver who grew up watching the car from behind the fence at the Nürburgring, it is a moment that still feels almost surreal.
But it is also one he has spent years earning.
