Pirelli closes final 2026 tyre test in Mexico City

The Pirelli 2026 F1 tyre test in Mexico City marked the final private development session before the post-season Abu Dhabi run, with Gabriel Bortoleto, Valtteri Bottas, and Frederik Vesti completing more than 1,200 kilometres across two days on the soft compound range from C3 to C6. The data gathered at altitude will shape Pirelli’s final construction and compound selection for next year’s Formula 1 season.

Key Points

• Final private Pirelli test before the post-season Abu Dhabi group session
• Two-day programme at the Autódromo Hermanos Rodríguez covering C3 to C6 compounds
• Bortoleto ran 136 laps for Sauber; Bottas and Vesti added 161 for Mercedes
• Track temperatures peaked at 51°C, total distance 1,278 km
• Focus: understanding soft-range degradation and structure stability before homologation

The end of the private phase

Mexico City. 2,200 metres up. Thin air, high heat, and no margin for cooling.
Perfect conditions for the final 2026 tyre trial before Abu Dhabi’s all-team test in December.

Pirelli ran two mule cars across two days, Sauber on Tuesday and Mercedes on Wednesday, to tie off the last variables in its prototype soft-compound programme. The goal wasn’t lap time. It was clarity. The numbers that decide what Formula 1 will race on next year.

Day 1 – Bortoleto on duty for Sauber

Gabriel Bortoleto handled opening duties in a Sauber C45-based mule. Fresh from scoring points in the Grand Prix, he switched from racing to research, logging data from the C3 through C6 compounds.

Morning runs were all about the gaps. How much quicker the C6 is than the C5. Where the C4 drops away. Short, controlled bursts before the asphalt baked past 45°C.

By mid-day, the test switched to longer 10 to 15-lap stints, stretching the softs through the long, sweeping Esses and the slow stadium section where thermal load punishes the rear tyres.

Bortoleto covered 136 laps, just over 585 kilometres, with a best of 1:19.089. Air clear, tarmac scorching. 51°C at the peak. A perfect snapshot for Pirelli’s degradation models.

Day 2 – Bottas and Vesti in the Mercedes mule

Wednesday belonged to Mercedes. Valtteri Bottas started early, running the same compound range but focusing on the C3. That tyre in particular sits on the edge of the 2026 baseline, soft enough to matter for qualifying, durable enough to survive stint one.

Bottas alternated between performance bursts and longer C3 runs to track grip loss as surface temperature climbed. He put in 112 laps, peaking at 1:18.204 late in the afternoon.

Then came Frederik Vesti, taking over for the evening stint. His job was different: structure testing. Multiple 10-lap runs, same fuel, same load, different internal designs. His quickest time, 1:19.657, was almost irrelevant. Consistency was the key number.

Together they logged 161 laps and 693 kilometres, in near-identical conditions to Day 1. Across the two days, Pirelli’s sensors recorded 1,278 kilometres of usable data under stable high-heat conditions. Exactly what the engineers needed.

What Pirelli learned

This test was never about chasing speed. It was about resilience.
The softest compounds have always been the tricky ones, quick out of the box but fragile once the heat soaks in. Mexico, with its low air density and limited cooling, is the ultimate stress test.

Pirelli’s engineers used it to finalise three key metrics:

1. Thermal range – how wide each compound’s performance window really is.
2. Degradation curve – how quickly performance fades across heat cycles.
3. Structural stability – whether the lighter 2026 casings maintain balance under heavy loads.

The target for 2026 is predictable performance without the overheating spiral that’s defined recent seasons. The construction now uses new polymer blends and a refined tread contour to lower surface temperatures and keep grip consistent for longer.

Mexico’s harsh environment gave the clearest read yet, and by all accounts, the numbers looked promising.

The road to Abu Dhabi

With Mexico done, the data now feeds into the final simulation block before Yas Marina.
That December 9 session will see all ten teams run the 2026 tyres in back-to-back comparison with their current specs. It’s the sign-off moment before FIA homologation. The last chance to tweak compound spacing, pressures, and carcass stiffness before production begins.

Coffee Corner Take – Pirelli 2026 F1 tyre test – Final Mexico City session concludes 2025

No noise. No glamour. Just substance.

Mexico closed the private phase of one of Pirelli’s most complex development cycles since returning to Formula 1. Two teams, three drivers, and almost 1,300 kilometres of running have quietly reshaped the baseline for 2026.

The real story sits in how much calmer these tyres now look. Temperatures under control. Grip drop-offs softened. Predictability up. For years the soft compounds were the wildcard in hot conditions, but here, at altitude, they held firm.

Bortoleto gave the engineers their control data. Bottas provided the comparative pace. And Vesti’s structural work proved the casing concept holds under repeated load. Between them, they gave Pirelli a platform strong enough to carry into the new regulations.

If the Abu Dhabi test confirms the same behaviour, Formula 1 might start 2026 with tyres that actually let drivers attack.
More laps on the limit. Less management. More racing.

That’s not revolution. It’s quiet progress. And it might be exactly what this new era needs.