SSC Ultimate Aero sets new world speed record! Is time to say Bye Bye! Veyron, as now the SSC Ultimate Aero Twin Turbo supercar is officially the "Worlds Fastest Production Car". For the new speed record to be accepted by the Guinness Book, Ultimate Aero TT needed to race down the selected course, turn around, and make a second pass in the opposite direction within one hour. This is to negate any discrepancy there may be in the course or conditions. Top speeds from each run are then averaged to obtain the official speed. This method has been used for decades as the benchmark for land speed record attempts. The Shelby Supercars Ultimate Aero (with 1,183hp) finalized speed testing with a World Record Breaking speed of 255.83 mph/ 411.76 kmh. The first pass was recorded at 257.11 mph/ 413.82 kmh, and the second pass was recorded at 254.55 mph/ 409.71 kmh. The official record was previously held by the Koenigsegg CCX (242 mph). The unofficial record held by the Bugatti Veyron is 253.4 mph.