Lei Jun apologises for slip at Xiaomi (小米) SU7 launch — "60+60 equals crashing into a wall at 120 km/h" remark

What Lei Jun said

Lei Jun (雷军), founder and CEO of Xiaomi (小米), has apologised for a slip of the tongue made during the March 19 launch of the new‑generation SU7 electric sedan. He wrote that he "misspoke" while explaining relative speed in a frontal offset crash and thanked netizens for pointing out the error. At the event he said two cars each travelling at 60 km/h have a relative speed of 120 km/h and that this is "equivalent to driving into a wall at 120 km/h," adding that the collision energy was 1.44 times the standard test condition.

Physics debate and test claims

The line triggered a lively physics debate online. Critics pointed out that from an energy perspective a head‑on crash of two identical cars at 60 km/h each does not mean each car experiences the same energy as a single car hitting a wall at 120 km/h — the latter would carry roughly four times the kinetic energy. Lei Jun said, and it has been reported that, according to tests by the China Automotive Technology & Research Center (中汽中心), a 50% offset frontal crash of two cars at 60 km/h each yields a collision energy 1.44 times that of the standard test condition — a technical point he cited but acknowledged his verbal mistake.

Why it matters

The episode is a reminder that figures and metaphors matter when tech executives talk about safety. Xiaomi is still a newcomer to the electric‑vehicle market compared with legacy automakers, and public trust around vehicle safety is a high‑stakes issue in China’s fast‑moving EV sector. Was it a simple slip of the tongue or a moment that exposed how easily technical nuance can be lost in a product pitch? Either way, Lei’s prompt clarification and thanks to online critics closed the loop — for now.