F1 Wind Tunnel Testing Rules Explained: The Sliding Scale (2026)
It sounds backwards: the team that wins the championship gets punished with less time to develop next year's car, while the team that finishes last gets rewarded with more. Here's exactly how F1's sliding-scale wind tunnel and CFD restrictions work, why they exist, and what they mean for the 2026 pecking order.
F1 Wind Tunnel Testing by the Numbers
- 320: baseline wind tunnel runs a team may use per two-month Aerodynamic Testing Period (ATP) at the 100% allocation level.
- 2,000: baseline CFD simulation runs allowed per ATP at the same 100% level, per Formula1.com's explainer of the sliding scale.
- 70%-115%: the full sliding-scale range -- from the championship leader (least testing time) to the last-placed team (most), moving in 5-percentage-point steps.
- 256: wind tunnel runs Red Bull was allocated for the first half of 2026 (80% of baseline) after finishing third in the 2025 constructors' championship, per The Race's team-by-team breakdown.
- 60%: the maximum scale of a physical model permitted in a restricted wind tunnel test, under the FIA's technical regulations.
- 50 m/s: the maximum airflow speed (about 112 mph) permitted during a restricted wind tunnel run.
How the Sliding Scale Actually Works
Every F1 team's aerodynamic testing allowance is measured over a rolling two-month "Aerodynamic Testing Period" (ATP). At the 100% baseline, that's 320 wind tunnel runs and 2,000 CFD simulations -- but almost no team actually operates at 100%, because the FIA adjusts each team's personal baseline up or down depending on where it finished in the previous constructors' championship standings. The team in first place is capped at 70% of the baseline; the team in last gets 115%; everyone in between is spaced 5 percentage points apart. The allocation isn't fixed for a whole season either -- Formula1.com's own explainer confirms it's refreshed twice a year, so a team that claws its way up the standings can see its testing time shrink again before the season is even over.
| Championship Position | Allocation | Wind Tunnel Runs / ATP | CFD Tests / ATP |
|---|---|---|---|
| 1st (least testing time) | 70% | 224 | 1,400 |
| 2nd | 75% | 240 | 1,500 |
| 3rd | 80% | 256 | 1,600 |
| 4th | 85% | 272 | 1,700 |
| 5th | 90% | 288 | 1,800 |
| 6th | 95% | 304 | 1,900 |
| 7th | 100% (baseline) | 320 | 2,000 |
| 8th | 105% | 336 | 2,100 |
| 9th | 110% | 352 | 2,200 |
| 10th (most testing time) | 115% | 368 | 2,300 |
The 2026 Season So Far: Who Has More Wind Tunnel Time?
Because the first half of 2026 is governed by the final 2025 constructors' standings, the teams that dominated last year are the ones with the tightest testing limits right now. Per Formula1.com and The Race's own reporting on the 2026 allocations: reigning champion McLaren opened the season at the 70% floor -- the smallest aero-testing budget on the grid -- while Red Bull, third in 2025, ran at 80% (256 wind tunnel runs and 1,600 CFD tests) and Ferrari, fourth, at 85%. It's a genuine competitive lever, not just a paperwork exercise: a team stuck at 70% has noticeably less room to chase the small aerodynamic gains that separate the front of the grid, which is exactly the point -- the scale is built to help teams behind the leader close the gap rather than let a dominant car's advantage compound further.
Why F1 Restricts Wind Tunnel Testing At All
Before 2021, wind tunnel testing was effectively unrestricted, and some of the best-funded teams ran their facilities close to around the clock, pouring money into aerodynamic development that smaller teams simply couldn't match. The FIA introduced the first version of the sliding scale in 2021 (a 90%-112.5% range) alongside the cost cap, then tightened it to today's wider 70%-115% range in 2022 as part of the same regulatory package aimed at leveling the playing field and making both individual teams and the championship as a whole more financially sustainable. Ahead of the all-new 2026 technical regulations, the FIA went further still and banned all wind tunnel and CFD work on next-generation cars entirely until January 1, 2025 -- mirroring the same freeze-then-release approach used before the last major rules reset in 2022, so no team could start developing the new-era car early just because it had extra cash to burn.
The Physical Rules: Model Scale and Airflow Speed
The restrictions aren't just about how many runs a team gets -- the FIA's technical regulations also cap what a "run" is allowed to look like. A model tested in a restricted wind tunnel session can't exceed 60% of the real car's size, and the airflow itself is capped at 50 metres per second, or roughly 112 mph. Teams are also limited to a single nominated wind tunnel for any 12-month period, declared to the FIA in writing, which rules out the old trick of hopping between multiple in-house or partner facilities to effectively multiply testing time.
Frequently Asked Questions
How much wind tunnel time does an F1 team get?
At the 100% baseline, a team can run 320 physical wind tunnel runs and 2,000 CFD simulations over a two-month Aerodynamic Testing Period. But almost no team actually sits at 100% -- the FIA's sliding scale adjusts that baseline up or down for every team based on where they finished in the constructors' championship, so the reigning champion runs at 70% (224 runs) while the last-placed team runs at 115% (368 runs).
Why do F1 teams get different amounts of wind tunnel time?
It's a deliberate handicap system introduced alongside the cost cap to stop the richest, most successful teams from simply out-developing everyone else. The team leading the championship gets the least aerodynamic testing time and the team at the back gets the most, in 5-percentage-point steps, so a struggling team has a built-in tool to help it catch up.
What is CFD in Formula 1?
CFD stands for computational fluid dynamics -- computer simulations that model how air flows over a car's bodywork without needing a physical model in a wind tunnel at all. The FIA caps CFD runs on the same sliding scale as wind tunnel time (2,000 simulations at the 100% baseline), because unrestricted CFD would let a well-funded team simply substitute computing power for the physical testing hours it's been denied.
How big are F1 wind tunnel models?
FIA technical regulations cap any model used in a restricted wind tunnel test at 60% of the real car's size, tested at airflow speeds up to 50 metres per second (about 112 mph). Each team may also nominate only one wind tunnel for its testing in any 12-month period, declared to the FIA in writing, rather than rotating between multiple facilities.
The Bottom Line
F1's wind tunnel rules are one of the sport's quieter but more effective competitive levers: instead of just capping how much money a team can spend, the sliding scale directly caps how much aerodynamic testing that money can buy, and does it in a way that automatically favors whoever is struggling most on-track. It's the same philosophy as the budget cap applied to a much narrower slice of the car -- and together, the two regulations are the biggest reason the gap between a dominant team and a backmarker has narrowed rather than widened over the past few seasons. For more on how the FIA keeps the on-track competition just as tightly regulated, our ground-effect aerodynamics explainer covers the technical side of what all that wind tunnel time is actually chasing.