The Veyron Super Sport set the official record back in 2010 with a Guinness-verified speed of 267.8 miles per hour, but other interested parties have recently contested that record's validity because the Veyron used that day had its speed limiter removed. With the speed limiter in place, the Veyron Super Sport tops out at 258 mph.
Guinness rules state that a record-setting production car must be unchanged from what is available to customers. While some, particularly Hennessey Performance, have claimed that removing the Veyron's speed limiter violated that rule, Guinness has settled the matter by stating that "a change to the speed limiter does not alter the fundamental design of the car or its engine."
This is a nice win for Bugatti on top of the news last week that the Veyron Grand Sport Vitesse also set a record for the fastest open-top production car with a speed of 254.04 mph. That record, however, as far as we know, has not been verified by Guinness World Records.
For its part, Hennessey, whose claim against the validity of Bugatti's record didn't work this time, could potentially break the record outright if given enough road for its own Venom GT to run. The 1,244-horsepower Venom hit 265.7 mph earlier this year before running out of room on a two-mile runway, though those runs were not officially verified by Guinness. Nevertheless, there still remain questions about whether or not the Venom GT counts as a production car by Guinness standards. The world record authority defines "production" as building at least 50 examples and only 29 Venoms are supposed to be built, though Guinness does permit itself to grant exceptions.
Guinness World Records statement: Fastest production car
Following a thorough review conducted with a number of external experts, Guinness World Records is pleased to announce the confirmation of Bugatti's record of Fastest production car achieved by the Veyron 16.4 Super Sport.
The focus of the review was with respect to what may constitute a modification to a car's standard specification.
Having evaluated all the necessary information, Guinness World Records is now satisfied that a change to the speed limiter does not alter the fundamental design of the car or its engine.