McLaren Endurance Racing team principal James Barclay has described a “great buzz” in the squad after it has already completed a successful 30-hour test of its new MCL-HY Hypercar at Motorland Aragon — an achievement Mikkel Jensen admitted was “more than we expected.”
The new machine had a first public outing at Varano in early May, but after just two additional runs at Imola and Magny-Cours — where the MCL-HY had already logged a full six-hour FIA World Endurance Championship distance — it went straight into the endurance program at Aragon last month.
Although there were occasional brief stoppages, mainly to verify potential issues flagged by sensors, there were no major interruptions as preparations ramp up ahead of the car’s planned debut in the World Endurance Championship in 2027.
Speaking from McLaren’s latest Silverstone test, Jensen said he was pleasantly surprised by how quickly the program progressed to long-format endurance runs compared with his experience on the Peugeot 9X8 Hypercar project.
“I can only judge from what I’ve seen before, and our belief in endurance testing was strong, but it took quite a while before it became a reality,” he stated.
“I was quite surprised by the mileage we achieved in Aragon. When you travel to a new venue for your first endurance trial, you never know what to expect, but the result was very positive, and I was impressed with everything the team has accomplished.”
Barclay stressed that it was crucial for McLaren to push the program early in order to determine if there were any significant reliability concerns with the MCL-HY.
“There are rivals who are running engines and components that have already proven themselves in other programs — whether in GT3 or other categories,” he explained.
“From one angle, our development path requires a bit more exploration, so we wanted an endurance evaluation sooner rather than later to see if there were any fundamental issues we needed to address.”
“What stood out positively is that we demonstrated a baseline level of reliability — that doesn’t mean perfection; we aren’t claiming to be finished, and we’ll keep refining — but tackling this so early in the test program was a significant challenge that we met.”
Barclay added that he was proud the project remained on schedule, having completed the 30-hour test without retiring early or cutting the program short, and that the team has already logged World Endurance Championship distances in previous evaluations.
“Our foundations look robust, but we’re not becoming complacent — there’s still a long journey ahead for the whole squad.”
He was cautious about disclosing specifics of the brief pauses during the Aragon run, but indicated that most of them related to the maturation of certain areas.
“Aero is one area where we’re making adjustments to various elements, and the durability of particular parts needs refining—things like fixings, attachments, and supports must be correct, so we’re methodically addressing those,” he added.
“You’ll likely notice some cooling-system updates on the car. We start conservatively and then determine what we can manage as we gain a better understanding of the conditions we encounter.”
“What we’re discussing here is iterative design tuning; there haven’t been any fundamental flaws.”
“We weren’t operating with a contingency plan in mind; we treated it as a race, making quick stops for checks if we judged that continuing could risk damage, and then we resumed.”
Barclay indicated that the current priority for McLaren is to demonstrate that the Aragon mileage isn’t a one-off, with further endurance tests planned to verify that it can sustain similar distances.
The emphasis is increasingly shifting toward performance testing, and he suggested that “visually there won’t be drastic changes to what you see now on the car” as the final parts specification is tightened.
Nonetheless, Barclay confirmed that McLaren remains fine-tuning the ultimate version of the twin-turbocharged V6 that powers the MCL-HY, concentrating on improving drivability as it approaches its final specification.
