Skid controversy explained: FIA claims unlikely to give advantage. An analysis of the alleged heated skid trick in F1 reveals that thermal expansion provides a negligible advantage.

Heated skids? Why the alleged illegal trick doesn’t hold up

Last night, the Japanese outlet AS-Web published a story that immediately made headlines, stirred controversy, and raised many questions. The rumor concerns an FIA inspection after the Sprint Race in Brazil, during which officials allegedly discovered a system allowing teams to bypass the regulatory limits on plank wear, letting the car run lower to the ground and gain a performance edge.

In short, the system reportedly involved the skid blocks, titanium plates that replace the plank in certain areas (see highlighted zones in the cover photo), while remaining perfectly aligned and protecting it from excessive wear. According to the rumor, some teams (or even most, as reported) were using a method to overheat the skids, causing thermal expansion to increase their thickness, touch the asphalt first (creating the sparks seen in every GP), and thus protect the plank, which is regulated to wear no more than 2mm. The FIA supposedly discovered this method and demanded its removal, forcing teams to raise their cars. While this might explain the sudden drop in performance for some teams in qualifying and the race, the claim doesn’t hold up under closer scrutiny. Here’s why.

What skids are and why heating them offers no real advantage

We ran some calculations ourselves (quite simple, actually) and found that the recent claims likely have no foundation. Let’s start with some key 2025 FIA regulations regarding skids mounted on the plank:

• Skids can replace the plank material (Permaglass, fiberglass+resin composite; previously beech wood) in certain points, but the total area of all skids must not exceed 24,000 mm² when viewed from below.
• No single skid may exceed 4,000 mm².
• Most importantly, skid thickness at installation: minimum 15 mm.
• Material: titanium alloy (AMS4928 or AMS4911).

We then checked titanium’s linear expansion coefficient:

αTitanium = 8.6 × 10⁻⁶ °C⁻¹

A quick formula to calculate thickness variation with temperature:

Δs = s₀ · α · ΔT

Where:
s₀ = initial thickness of the titanium
α = linear expansion coefficient
ΔT = temperature change (°C)

Applying this formula, the original 15mm thickness becomes:

• 15.0129mm at 100°C
• 15.0387mm at 300°C (average race temperature)
• 15.0645mm at 500°C

Even assuming skids could be heated to 500°C, the increase in thickness toward the ground would be only half the total expansion, roughly 0.03mm. This “protection” is minimal, considering the plank wear tolerance is 2mm and that Hamilton, for example, was disqualified in China for 0.5mm — 15 times larger than the alleged thermal expansion effect.

Even if teams used thicker skids (allowed by regulations) and embedded them deeper into the floor, thermal expansion alone would provide negligible extra protection. Heating skids would also consume valuable electrical energy, and thicker skids would weigh more.

Explaining the performance drop

So how to explain the drop in performance between the Sprint Race and qualifying for some teams? Without invoking hypothetical systems, the simplest explanation is that teams set cars lower for the shorter sprint race, knowing plank wear would be reduced due to fewer laps, lighter fuel load, and less abrasion. Some cars manage downforce and balance even at higher ride heights, others less so.

Some anomalies from the Brazilian weekend remain puzzling: Haas’ unusually high performance, Max Verstappen’s Red Bull setup issues resolved only on Saturday night, Piastri vs. Norris, Russell vs. Antonelli, Ocon vs. Bearman. Yet the most straightforward explanation is that teams varied setups between drivers, sometimes only finding the optimal setup for one of the two due to changing conditions.

These are our considerations. We have asked the FIA for clarifications, but most likely this rumor is baseless.

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