British driver Andy Green has achieved a new milestone in automotive engineering by setting the fastest speed ever recorded for a hydrogen-powered car. During a recent test run, Green reached a top speed of 406mph (654km/h).

While the report notes that Green "broke the sound barrier," it is important to clarify the physics involved in this claim. The speed of sound at sea level is approximately 767mph (1,235km/h). At 406mph, the vehicle is traveling at roughly Mach 0.53, which is significantly below the speed of sound. The BBC report characterizes the achievement as breaking the sound barrier, though the provided speed data indicates the vehicle remained well within subsonic limits.

This record-setting run highlights the increasing performance capabilities of alternative fuel vehicles. Hydrogen technology is currently being explored as a sustainable path for high-performance automotive engineering, moving away from traditional fossil fuels. Green, who is known for his history in land-speed record attempts, continues to be a central figure in testing the limits of experimental vehicle propulsion.