What car upgrades are allowed in F1?
Teams can keep developing their cars' aerodynamics and bodywork all season, bringing upgrades race by race, as long as the parts pass crash tests and fit the rules. What limits them is the budget cap, a sliding scale of wind-tunnel and CFD time that gives lower-placed teams more, a power-unit freeze, and parc ferme, which locks the setup once qualifying begins.
Aero upgrades never really stop
Unlike the power unit, a car's aerodynamics and bodywork are not frozen, so teams develop and bring new parts throughout the season, which is why you hear about a "B-spec" car or a big upgrade package for a particular race.[2] New parts still have to comply with the technical rules, and the car must pass its homologation crash tests, which the FIA keeps at least as strict as the year before.[5]
The budget cap
The biggest brake on development is the cost cap, around 135 million dollars in 2024 and 2025 with a small allowance for each extra race on the calendar.[1] It covers car design, development and most staff, but leaves out driver salaries, the highest-paid team members and marketing, and the figure is adjusted each year.[1] Because every new part is counted, the cap forces teams to choose which upgrades are worth the spend.[1]
Wind tunnel and CFD on a sliding scale
Aerodynamic testing is rationed too, on a sliding scale set by championship position and reset through the season.[2] The team leading the constructors' standings gets the least wind-tunnel and computer-simulation time, and the lower-placed teams get the most, a deliberate handicap meant to help the field close up rather than let the leaders pull away on development.[2]
The engine freeze and parc ferme
Power units are a different story: they are homologated and frozen within a regulation era, so manufacturers cannot keep chasing engine performance the way they chase aero.[3] And once a car leaves the pits for qualifying it enters parc ferme, where the setup is locked until the race, so any upgrade has to be fitted and signed off before qualifying starts, not bolted on overnight.[4]
:::analysis The picture that emerges is a sport trying to keep competition open without freezing development entirely. Aero stays free so teams can out-think each other, but the cost cap and the wind-tunnel handicap stop the richest or fastest team from simply developing its way to a permanent advantage. It is managed competition, not a free-for-all.
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Related reading
- [1]F1 cost cap: what is it and how does it work? (Motorsport.com) (motorsport). Accessed 2026-06-19.
- [2]The aero testing restrictions each F1 team faces (The Race) (the-race). Accessed 2026-06-19.
- [3]Engine freeze agreed (Formula1.com) (formula1). Accessed 2026-06-19.
- [4]FIA Insights: how parc ferme works (FIA.com) (fia). Accessed 2026-06-19.
- [5]2026 regulations explained: aerodynamics (Formula1.com) (formula1). Accessed 2026-06-19.