Six Hours of the Glen preview: LMP2 returns to IMSA

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Just a week after Le Mans, the IMSA WeatherTech SportsCar Championship roars back to life this weekend with the Six Hours of The Glen, a crown jewel of North American endurance racing.

With all four classes returning to action and 56 cars entered, this is the largest field since March’s 12 Hours of Sebring. And for teams, drivers, and fans alike, it’s far more than just another date on the calendar—it’s a pivotal moment at the halfway mark of the 2025 season.

There’s a buzz surrounding this event, and not just because of the car count. A sizable portion of the field competed in last weekend’s 24 Hours of Le Mans, with many making the transatlantic dash to regroup and refocus on championship aspirations in upstate New York.

Watkins Glen represents Round 3 of the IMSA Endurance Cup and race 6 of 11 on the full-season schedule. For many, it's the first real opportunity to shift from survival mode to title contention.

2024 winners at Watkins Glen

GTP: Felipe Nasr/Dane Cameron, #7 Porsche Penske Motorsport Porsche 963 

LMP2: Luis Perez Companc/Nicklas Nielsen/Lilou Wadoux, #88 Richard Mille AF Corse ORECA LMP2 07

GTD PRO: Ross Gunn/Alex Riberas, #23 Heart of Racing Team Aston Martin Vantage GT3

GTD: Russell Ward/Philip Ellis/Indy Dontje, #57 Winward Racing Mercedes-AMG GT3

35 previous Watkins Glen winners entered

A stacked field of talent will take the green flag at Watkins Glen this weekend, with 35 previous race winners returning to chase more glory across the IMSA classes. Among them, Felipe Fraga and Gar Robinson stand out with three straight LMP3 victories from 2021 to 2023.

Familiar faces like Filipe Albuquerque, Dane Cameron, Antonio Garcia, and Ricky Taylor bring multi-year winning experience across prototype and GT ranks. Recent winners such as Ross Gunn and Felipe Nasr enter, with momentum from their 2024 triumphs. Meanwhile veterans like Spencer Pumpelly and Joey Hand add even more depth with victories dating back almost a decade or two, respectively.

The list spans every class—defunct or not—setting the stage for one of the most competitive editions of the Six Hours of The Glen in recent memory.

The big guns are back

In the headlining GTP class, we’re seeing a return to full strength. Thirteen entries—tying the season high from Sebring—will take the green flag. That includes the return of Proton Competition’s #5 Porsche 963 and Lamborghini’s #63 SC63, run by Riley Motorsports as of this year on behalf of the Squadra Corse factory.

With the global prototype calendar beginning to settle, this is the moment when these cars can begin stacking consistent results.

Over in LMP2, fans will be pleased to see the class return for the first time since Sebring. The field features the same 12 cars that opened the season with nail-biting competitiveness. Among them, Riley Motorsports #74 and Inter Europol’s #43 are locked in a battle that’s separated by just two points.

Don’t count out AO Racing either. With a win at Le Mans in the LMP2 pro/am subclass under their belt, Spike is looking for his first LMP2 IMSA win. So far, the class has delivered two different winners in two rounds—and there’s every indication that trend could continue.

The GT ranks are just as fierce. GTD Pro returns with 10 entries, featuring top-tier factory and semi-factory programs eager to gain ground in the Michelin Endurance Cup. Meanwhile, the GTD class sees a healthy 21-car field, many of which are Endurance Cup-only programs returning for the endurance-focused rounds. The sheer volume and depth of competition in both GT categories virtually guarantees six hours of relentless action, pit strategy trickery, and class-by-class chess.

Mid-season means momentum — or pressure

With the season hitting its halfway point at Watkins Glen, the standings are beginning to take shape, but nothing is secure.

The championship battles remain highly competitive. In GTP, just 70 points separate first from second—not a comfortable margin given the chaos that often unfolds at The Glen.

LMP2 is the tightest of the lot, with that razor-thin two-point gap mentioned earlier. GTD Pro is nearly as close, with an 11-point swing between the top teams, while GTD sees the largest spread at 124 points—but even that can evaporate over a couple of races.

Watkins Glen, with its elevation changes, flowing corners, and mercurial weather, has a reputation for shaking things up. It’s not just a test of speed but also of stamina, consistency, and focus over six hours.

Breaking Streaks

Coming into the Glen, there’s a new narrative: the streak breakers. At Detroit, Acura upset BMW’s four-race pole streak and ended Porsche’s run of GTP victories with a strong showing from the #93 Acura ARX-06 fielded by Meyer Shank Racing.

Nick Yelloly, defending GTP winner at Detroit and LMP2 winner at Le Mans, spoke with Only Endurance about their testing at Watkins Glen earlier in May, on an IMSA-hosted Zoom call.

'So the last two days we were actually out there [Watkins Glen] testing,' Yelloly said.

'The out-laps can be quite treacherous at the best of times in the GTP class, particularly when you're going out on the harder tyre. So it was quite interesting to have a go with those without too much traffic on the circuit. So you could try and really push the out-laps and see where the limit was.'

'It's an awesome track. The first few laps definitely take a bit of adjusting because of the, well, not the closing speeds, but the entry speeds you're really shifting on. But I think we went through a great test program with both cars really sharing the workload well. And I think between us all, we came away with a lot of data that we can, yeah, siphon through.'

In GTD PRO, Ford struck gold—breaking AO Racing’s dual-class win streak with a commanding performance from the #64 Mustang GT3.

The question now is, was that a one-off spark or the start of a trend? Acura and Ford have momentum, but whether they can turn it into dominance—or whether their rivals will respond—is one of the weekend’s biggest storylines. 

History doesn't repeat itself

History tells us not to bet on repeat winners at Watkins Glen—at least not in the GTP class. The last four years have seen four different manufacturers take the overall win. Porsche triumphed in 2024, BMW in 2023, and Acura in 2022.

In 2021, when IMSA held two events at the Glen due to pandemic-related reshuffling, the short-format race went to Cadillac, and the longer six-hour race was won by Mazda.

This kind of parity is almost unheard of in top-tier sports car racing. The Glen’s blend of high-speed sections and technical turns doesn’t favor one particular car over another, making it a driver’s circuit—and a strategist’s nightmare.

IMSA Endurance Cup returns

Finally, this race marks the return of the Michelin-sponsored Endurance Cup, a championship within the championship. Points are awarded not just at the finish but also at the three-hour mark, rewarding consistency and long-game strategy.

The scoring format is simple but punishing: five points for first at each mark, four for second, three for third, and two for the rest. With so much still to play for, the teams focusing solely on the endurance championship will be just as aggressive as those chasing season-long glory.

Final thoughts

Watkins Glen is more than just a six-hour race—it’s a pressure cooker, a proving ground, and a mid-season milestone all in one. The field is full, the storylines are tangled, and the stakes couldn’t be higher. For some teams, it’s a shot at redemption.

For others, it’s a chance to take control of their championship fate. Either way, when the green flag drops, the battle will be relentless—and the outcome, unforgettable.