Continental has entered the Guinness Book of World Records with a top speed of 242 mph (388 km/h). We're definitely not talking about the behemoth Bentley, as powerful as it is. The record now officially belongs to Continental Tires for its ContiSportContact Vmax, which has been officially certified by those stout-chugging judges as the world's fastest production road tire.
The rubber was tested on the 9ff-modified Porsche 911 that took the world record for the fastest street-legal road car. A custom 9ff cabrio also took the record for the world's fastest convertible with a high end of 237.8 mph (380.5 km/h). Both cars are owned by 9ff chief Jan Fatthauer, and the top speed runs were certified by Guinness.
If you're thinking that the Bugatti Veyron (and the purpose-made Michelin rubber on its wheels) can hit a higher speed, you may be right, but the Veyron has yet to try for the official record, and its tires were specially made for the Bugatti, while the Continentals are offered to the public as standard production road tires. As much as the car's own capabilities, how it makes contact with the road (i.e., its tires) often dictates a car's limits. Just keeping the tires from melting (as they do on the Veyron after just 12 minutes at its 253-mph top speed) is a feat in and of itself.
[Source: Motor Authority]