Pirelli arrived at Bahrain knowing 2026 was going to be odd. New cars, a new aero philosophy, and a fresh layer of complexity in the form of active aerodynamics — all landing on tyres that, at a glance, don’t look wildly different to what we’ve had.
But in the details, it’s a very different job. The 18-inch diameter stays, yet the rubber is narrower and lighter: 25mm trimmed from the fronts and 30mm from the rears compared to last year. F1’s pushed for lighter cars and a shift away from four seasons of ground-effect dependence, leaning more on over-body airflow for downforce. In parallel, the power unit rules have swung more emphasis onto electrical output, and that brings its own punch in acceleration forces.
The headline change, though, is what drivers are already calling the new normal: active aero that’s not a gimmick, but a core operating mode. DRS has been replaced in spirit by a system the cars live on every lap. In ‘Straight Line Mode’, front and rear wings flatten on the straights to cut drag and bleed downforce. Before the braking zone, the wings snap back into ‘Corner Mode’ and the car regains load for turn-in.
It’s a fundamental shift in how forces arrive at the tyre. In 2025, the peak stress point Pirelli monitored most closely was often the end of the straight — big load, big speed, heavy braking, camber sensitivity. Now, that picture has been scrambled. The straights themselves can be comparatively kinder in terms of vertical load because the wings are flattened, even if the speed is higher and standing waves remain part of the conversation. Then the spike comes: a rapid restoration of downforce at exactly the moment the car transitions from low-drag to high-load running.
Pirelli’s Mario Isola, speaking after Friday’s running in Bahrain, said the early signs are reassuring — with a big caveat. Teams are still keeping plenty in their pocket.
“At the moment, we’re quite aligned, but I believe that teams are not pushing at the limit,” Isola said. “So I’m expecting to see forces increasing for the next session.”
That’s the tightrope Pirelli has been walking since the tyres were homologated on December 15, 2025. The programme to sign off the 2026 construction was extensive, but it had to be done without any true 2026 car existing in the flesh. Like so much of modern F1, it leaned heavily on simulation and mule-car running. Only now, with two tests’ worth of real data, can Pirelli begin to replace assumptions with evidence — and even then, it’s evidence gathered while teams are deliberately avoiding the cliff edge.
Isola’s explanation of how the load has moved is telling. On many circuits, what matters most is still high-speed cornering — Silverstone and Suzuka will always be the real exam papers — but the straights have changed character. “Now, on the straight, they don’t push the tyres a lot into the ground,” he said. Higher speed, less load. And then, abruptly, the opposite.
“When they close the straight mode, the load on the car is much higher,” Isola added. “So there is a peak when they close it and this additional load is through the corner. When we defined the prescriptions, we had to consider all that.”
Anyone watching from the end of Bahrain’s back straight didn’t need the data overlay to notice it. The car’s attitude changes sharply as Corner Mode returns; you can almost see the downforce arrive as a vertical hit across both axles. It’s not hard to wonder whether some of the lock-ups seen across the test are connected — whether the timing of that load spike, combined with lift and initial brake pressure, is unsettling the platform just enough to provoke a front snatch. That’s speculation for now, but it’s the kind of detail that can turn from curiosity to pattern once performance gets unleashed.
The bigger question, and the one that will keep Pirelli’s engineers awake once the season actually begins, is what happens when the system doesn’t behave.
DRS failures were rare and usually manageable because DRS was optional. This isn’t. The 2026 cars are designed around that drag reduction being there, lap after lap. If ‘Straight Line Mode’ fails and a car gets stuck in Corner Mode, you’re suddenly running peak downforce — and therefore peak vertical load — for much longer periods, at much higher speeds, than the regulations have effectively assumed.
Think about the long, flat-out sections at places like Jeddah, Baku or Las Vegas. A car pinned in Corner Mode down those straights would be asking the tyre to live under sustained load at speed. Not for a single braking event, but for an entire straight, repeatedly, potentially for laps if the driver chooses not to pit.
Isola made it clear Pirelli has had to write prescriptions with the working and non-working scenarios in mind — not just for dry running, but for wet conditions too. “There is another complication that is if the system is closed, or only partially open, in case of wet conditions,” he said.
Pirelli’s current baseline assumption is that slick-tyre running will be with the system functioning, while intermediates and wets are considered with the system not working — a sensible split given how teams may choose to operate in low grip. Crucially, teams aren’t obliged to deploy Straight Line Mode even on slicks, but Isola isn’t expecting anyone to take that option because of the practical knock-on: higher downforce on the straights increases the chance of grounding the floor.
The thorny bit is the realistic race scenario. A system issue late on, with points on the line, and a driver with a gap behind? They’re not voluntarily parking it. Isola said as much: “If you have 10 laps to the end and the driver is running with 30-seconds advantage… he’s not going to stop.”
That opens up an uncomfortable governance question: could an aero malfunction become a tyre safety concern, rather than purely a performance problem? Asked whether a straight-line failure could, in theory, lead to a black-and-orange flag if the tyre risk over a stint became unacceptable, Isola admitted it isn’t something that’s even been properly discussed yet.
He’s betting on reliability — “99 per cent of the time” — and noted he hasn’t heard of significant issues during the test. But if that percentage proves optimistic once racing starts, the sport may find itself having to decide whether an active aero failure is something you manage strategically, or something the officials police for safety.
For now, Pirelli is where it often is at this stage: cautiously calm, quietly wary, and waiting for the moment the teams stop sandbagging and start generating the real numbers. In 2026, the tyres aren’t just responding to speed and downforce — they’re responding to a car that changes its aerodynamic state several times a lap. That’s a new kind of load story, and Bahrain has only given us the opening chapter.
