The 2026 F1 power unit rules were meant to level the playing field between works teams and customer teams. Two rounds in, the opposite has happened at Mercedes — and its customers are only now grasping the scale of the problem.
The clearest read came after a Melbourne race in which the McLaren of reigning champion Lando Norris finished more than 50 seconds behind the works Mercedes pair. Both teams are running the same Mercedes-HPP power unit. Both are operating under technical regulations that place strict limits on what a manufacturer can do differently for itself versus its customers. Yet the timesheet told a story nobody in the McLaren or Williams garages had expected.
The scrambling behind the scenes has been documented by The Race, whose analysts pieced together a picture of shock inside the customer teams that the works Mercedes outfit had produced so much more from an engine they all nominally share.
Williams team boss James Vowles — himself a former Mercedes strategist — did not bother disguising his surprise. According to paddock reporting, Vowles admitted the team was caught off guard by what Mercedes unleashed in Melbourne and estimated Williams was losing around three-tenths of a second a lap on engine power alone, despite running the same hardware.
That is a remarkable figure under 2026 regulations. The rules were framed around the idea that the power unit would be a more tightly controlled commodity than under the previous hybrid cycle. Customer teams sign up on the understanding that the engine they receive will perform identically, or near-identically, to the one fitted in the works car on the grid alongside them.
The issue, The Race's analysis suggests, lies not in the hardware but in the mapping, calibration and real-world deployment strategy built up by Mercedes over years of in-house testing. The works team knows every corner of its own product. The customers are, in effect, paying for the same engine but not the same operating manual.
Andrea Stella, McLaren's team principal, has been openly puzzled by the delta. Having knocked Mercedes off the top of the Constructors' standings only in recent seasons, McLaren expected to start 2026 on a level footing — not trailing its engine supplier by almost a minute across race distance. By The Race's own account, most of the gap between the two teams in Melbourne could not be explained by chassis performance. It had to be engine understanding.
That is a politically awkward position for Mercedes. The team has always publicly committed to supplying its customers on equal terms. Yet the 2026 rule set, with its extraordinarily sensitive electrical deployment and recovery windows, rewards deep familiarity with the power unit in ways the paper regulations did not anticipate. Mercedes has that familiarity. Its customers do not.
There is also a commercial reality. McLaren is no longer a friendly customer in the traditional sense — it is a title rival. Why would Mercedes voluntarily hand over the insights that allowed it to pull 50 seconds clear in Melbourne to the team it is now trying to re-overtake?
For Williams, which has rebuilt its engineering capability under Vowles and which signed its long-term Mercedes deal partly to avoid exactly this kind of surprise, the message is equally unwelcome. Three-tenths a lap to the works team is not a gap that can be closed with chassis upgrades alone. It has to be closed on the dyno, in the software, and in the hours of simulation work only Mercedes has put in.
The broader implication for 2026 is uncomfortable. Under the new power unit formula, the team that builds the engine appears to have a structural advantage nobody costed in when the regulations were signed. If Melbourne was not a one-off, expect McLaren, Williams and other Mercedes-powered outfits to push hard behind the scenes for either more shared data — or, failing that, a fundamental change to how customer units are supplied.
Until then, the 2026 Mercedes story is not just the works team's impressive early pace. It is the gap it has opened up on teams using its own product.
