I saw media outlets testing the Xiaomi YU7 on a track where the brake pads caught fire. What is happening here?
In the video, the Xiaomi YU7 Max completed one warm-up lap followed by one flying lap at the Tianjin V1 Racing Circuit. Under extreme conditions without a cooling lap, it parked directly. The high temperature caused the organic material in the brake pads to catch fire, but the braking system as a whole did not experience any brake failure or other issues; its functions remained intact and usage was normal.
Additionally, the test vehicle did not use the "Enhanced Energy Recovery" feature in the Xiaomi YU7 Max Master Mode. This feature enhances energy recovery intensity during track conditions, reducing the load on the mechanical braking system. Even if ABS wheel lock occurs, it can still provide maximum 0.2G of braking energy recovery, effectively reducing the occurrence of extreme situations where the braking system temperature exceeds 600°C.
During track driving, vehicles often need to perform emergency braking from ultra-high speeds, placing a much higher load on the braking system than in daily driving. Under these conditions, brake disc temperatures rise sharply. If effective cooling is not adopted, it can lead to material ignition. Meanwhile, as a mid-to-large SUV, the Xiaomi YU7 has a higher curb weight compared to smaller SUVs, and its high power output leads to faster tail speeds on the track, making heat generation in the braking system more pronounced during intense braking. Therefore, effective cooling is a very crucial and basic piece of knowledge for track driving.
The Xiaomi YU7 Max uses low-metallic brake pads containing organic materials such as metal fibers, abrasives, and resins. Resins and other organic materials undergo polymer branch chain decomposition reactions at high temperatures (generally above 300°C), producing gases such as water vapor, carbon monoxide, carbon dioxide, alkyls, and aromatic compounds. Some of these combustible gases may produce brief flames under high temperatures (generally brake disc temperature > 600ºC) and sufficient oxygen. This is a normal physical phenomenon, but braking performance will not fail.
The Xiaomi YU7 is positioned as a city luxury high-performance SUV. We strongly advise everyone to prioritize driving safety. Do not rashly attempt track driving with unmodified factory cars without professional upgrades and preparation. Driving skills should be learned and advanced gradually only after fully understanding the product's performance boundaries and possessing professional driving knowledge. If attempting professional track driving, necessary upgrades to the vehicle's tires, braking system, and cooling system are required, along with using Master Mode and enabling the Enhanced Energy Recovery function to avoid safety hazards under extreme conditions.