m5board.com presents: Several minutes on the unrestricted Autobahn in Germany. Several minutes on the top speed limiter in the night. Speed is 270 km/h on the speedometer and 260 km/h for "real" as measured by GPS satellites. The car is limited to 260 km/h from the factory but does over 300 km/h on the speedometer when unlimited.
Top speed BMW M6 Gran Coupe 190 mph limiter 305 km/h at German Autobahn GPS-verified Video Vbox