Xiaomi SU7 Ultra Hit 203 km/h Before Fiery Fatal Crash: Forensic Report

A forensic report into a fatal crash involving a Xiaomi SU7 Ultra found the vehicle was traveling at 203 kilometers per hour 3 seconds before impact and 167 km/h at the moment of collision, with investigators concluding the driver died in a post-crash fire rather than from the initial impact.

According to Caixin today, citing a judicial appraisal opinion issued by the Sichuan Huaxi Traffic Judicial Appraisal Center, the vehicle was severely speeding when it struck a car traveling in the same direction in Chengdu in southwest China's Sichuan Province on October 13, 2025.

The report determined that the crash caused deformation of the power battery, leading to internal cell short-circuiting. High-voltage electricity then intruded into the low-voltage circuit, cutting off the vehicle’s low-voltage power supply.

As a result, the exterior electronic door handles failed after the collision because the low-voltage system lost power. The vehicle’s design relied solely on electronic exterior door releases and did not include a mechanical emergency handle outside the car. An interior mechanical emergency release was installed but located at the bottom of a storage compartment.

Investigators concluded the driver died from fire-related injuries after the vehicle ignited, rather than from immediate trauma caused by the collision.

Police in Chengdu said earlier that the crash occurred around 3am on the southern section of Tianfu Avenue. The 31-year-old male driver, surnamed Deng, collided with a vehicle ahead before crossing a central median and catching fire. Authorities said he was suspected of drunk driving and bore full responsibility for the accident.

Online videos showed several passers-by trying to break open the door as the car was engulfed in an inferno, but to no avail.

In response to safety concerns raised about the first-generation SU7’s lack of external mechanical door release, Xiaomi has upgraded newer models. The updated SU7 now features semi-concealed door handles equipped with a mechanical unlocking structure that allows manual opening in extreme scenarios such as power failure.

The company’s newer YU7 model adopts a similar safety redundancy design, with inward-folding exterior handles covering a mechanical cable structure and an independent backup power supply for the door lock system located beneath the second-row seats, ensuring door operation even if both the main battery and auxiliary battery lose power.

The upgraded design complies in advance with China’s mandatory national standard “Safety Technical Requirements for Automobile Door Handles,” set to take effect in 2027. The regulation requires all vehicle exterior door handles to include a mechanical release function to ensure that non-collision-side doors can be manually opened after an accident.