US firm Hennessey's Venom GT set the new record for the fastest car in the world during a test run at the Kennedy Space Centre in Florida.
Venom beat the previous best record of 431km/h set by Bugatti Veyron Super Sport.
Venom GT is a stretched Lotus Exige with a 7.0-litre, 927kW twin-turbo V8 wedged between its axles.
The record is impressive as test driver Brian Smith started from rest, broke the record and stopped on a 5.1-kilometre stretch of tarmac rather than using an high-speed oval to give the car a running start, 'Drive.com' reported.
"If we could run on an 8-mile (12.8km) oval we could go faster than that," Smith said.
However, Bugatti will retain its place in the Guinness book of records, the report said.
The independently verified Hennessey speed will not go into the book as the Venom could only be driven one way on the NASA landing strip.
The book requires cars to make runs in two directions to account for variables including gradients and wind direction.