The antepenultimate round of the 2025 IMSA SportsCar Championship took place on Sunday at legendary venue Road America. A quintessential American-style, 160-minute race, it featured five safety car periods, forcing teams to gamble on strategic choices.
Just weeks after officially announcing their split at the end of the current season, BMW M Motorsport and Team RLL had their boldness rewarded with a 1-2 finish. In contrast, Porsche, which looked set for victory, lost everything in a matter of seconds when Nick Tandy made contact with the #10 Cadillac while fighting for third place.
Despite finishing fifth and eleventh, Porsche Penske Motorsport retains the lead in the constructors', teams', and drivers' standings with two rounds remaining.
Porsche caught out by American way of racing
Unlike in the World Endurance Championship, Balance of Performance changes in IMSA affect performance but do not necessarily remove cars from contention for victory. Weight and power disparities are smaller, and the frequent safety cars constantly erase gaps.
The Porsche 963 was again heavier and less powerful than its rivals, resulting in disappointing fifth and eighth places in qualifying. But after the second yellow flag, 23 minutes into the race, Matt Campbell and Felipe Nasr were called in for fuel. Rejoining in 10th and 11th, they gained an advantage by the end of the first hour.
Because the cars required less fuel than their rivals, Mathieu Jaminet rejoined the track at the front of the field in the #6, three positions ahead of Nick Tandy in the #7. A win seemed possible, until just under an hour from the finish.
More sportscar racing coverage on The Race
- Lamborghini becomes first major manufacturer to quit Hypercar
- Hypercar boom future rests on a big rules decision
- What's behind BMW and Rahal's big sportscar split
While battling for third place, Tandy and Ricky Taylor made contact. The #10 Cadillac spun and, although Taylor managed to get going again without assistance, race control opted for a debatable yellow flag. The move favoured BMW (see below) and destroyed the race for both factory Porsche 963s.
Forced to pit again while both BMWs had already done so, the two Porsches were third and fourth at the next green flag. Tandy was also handed a harsh 60-second stop-go penalty for causing the incident, dropping him to 11th in the GTP class.
On the restart, Jaminet was powerless against the #93 Acura ARX-06, which was 13kg lighter and had around 20kW more energy than the Porsche 963. Jaminet was then overtaken by the #31 Cadillac V-Series.R of Action Express Racing and ultimately finished fifth.
"We made the right decisions during the race and brought both Porsche to the front," summarised Jonathan Diuguid, Porsche Penske Motorsport managing director.
"Congratulations to BMW, they chose a bold strategy during the final yellow phase and were duly rewarded. Overall, it was an acceptable result; we remain first and second with both Porsches.
"Hopefully, we can demonstrate stronger performance in Indianapolis and be more competitive again, particularly in terms of top speed on the straights, something we sorely lacked here."
Jaminet and Campbell extended their lead in the drivers' championship over their team-mates, who remain in second place, 75 points back.
BMW finally capitalises on its speed
Next year, Team RLL will no longer run BMW's IMSA programme, with the manufacturer switching to WRT. But before they part ways, the two parties are determined to shine.
For most of the race, the two M Hybrid V8s didn't appear to be contenders despite a favourable BoP. But with an hour to go and nothing to lose, they chose to make their final stops early, betting on a fifth yellow flag.
The racing gods delivered: it came just seven minutes later, allowing them to stay out while all their rivals had to pit. At the final restart, 38 minutes from the finish, the two cars were running first and second - the #24 of Dries Vanthoor and Philipp Eng ahead of the #25 of Marco Wittmann and Sheldon van der Linde - where they remained until the finish.
"This time we finally managed to turn it into a win after struggling earlier in the season to fully capitalise on our speed," Vanthoor said. "The team was amazing, and the strategy call was perfect."
Thanks to the M Hybrid V8's third-ever win and first of 2025, BMW climbs to third in the drivers' (Vanthoor-Eng), teams', and constructors' championships.
Acura's frustration
Starting from pole position, the #93 Acura ARX-06 from Meyer Shank Racing hoped to deliver a third-consecutive win for Acura to keep pressure on Porsche in the championship. But having suffered from Porsche's strategic gamble early on, Acura was then undone by BMW's bold move late in the race.
"Road America is always exciting, but it's always a bit of a gamble somehow with the strategy here and that's the way it turned out again," Renger van der Zande explained.
"The BMWs were towards the back, and they took a gamble on when they pit and they won."
Thanks to a strong restart from Van der Zande, the #93 managed to finish third, overtaking both factory Porsche 963s in the process.
The sister #60 car, however, finished seventh, in part due to a drivethrough penalty for a pitlane infringement.
Cadillac still winless
Of the four title-contending manufacturers, only Cadillac has yet to win a race this season despite now fielding three cars instead of two. The V-Series.Rs never truly contended for victory at Road America, but two of them had a shot at the podium.
The #10 of Wayne Taylor Racing had its hopes vanish when Taylor spun just under an hour from the finish in the collision with Tandy.
"It's just frustrating because I think we had the pace to [match] the BMWs that finished 1-2," Filipe Albuquerque said.
Meanwhile, the #31 from Action Express Racing was running second before being caught out by BMW's bold strategy. It was a frustrating outcome, especially as Earl Bamber later stole fourth place from Jaminet.
With steady progress in the WEC - pole at Le Mans and a first win at Interlagos - Cadillac now needs to avoid finishing the IMSA season winless. Only two races remain to make sure that doesn't happen.
