F1 Testing Day 3: Rumors suggest Mercedes is cranking up new 2026 engine

Mercedes has underlined its status as one of the talk-of-the-paddock teams following Formula 1’s third day of private 2026 testing in Barcelona. It’s understood, however, that the Brackley-based team has already been turning up its state-of-the-art power unit over recent days, although the true potential is yet to emerge. The final day of running was a session in which teams ran extended stints, honed aerodynamic concepts, and discreetly evaluated themselves under the new rules.Mercedes has been the subject of much attention as observers have been surprised at their straight-line performance and strong race pace over longer stints. Teams are not offering much in the way of details, but inside the paddock, there are whispers that Mercedes could be further down its 2026 development cycle than some rivals. As the sport was trending toward a significant technological reset, any early benefit could have been crucial.Mercedes’ on-track programme certainly looked very slick and efficient on day three, with George Russell stacking up lots of laps without outward signs of anything reliability-related. Engineers were concentrating on system checks and power delivery rather than outright lap time, but the car looked to have excellent stability under acceleration and in medium-speed corners.George Russell is understood to have been positive about it, especially when it comes to driveability and energy deployment. Insiders indicate that Mercedes has done a good job of packaging the new power unit with its chassis and cooling layout, an area in which it’s caught other manufacturers out during early testing. Mercedes did not release official time sheets, but rival teams allegedly began taking note of the pace during longer runs.Part of the talk in the pit lane has been about whether Mercedes is already pushing its 2026 power unit closer to the edge than others. The rules may heavily favour electrical output and energy management now, with a general sense that Mercedes have stumbled across an Energy F1 efficiency “sweet spot” between the internal combustion engine and deployment of the hybrid application.Although no team has officially made a complaint, rival engineers are believed to be closely monitoring the situation. Any sense of an early advantage would bring closer inspection as testing goes on in Bahrain. It's all just speculation at this point, of course, but you have to keep noticing Mercedes' form.