The Koenigsegg Agera RS is now officially the fastest production car in the world. As we reported yesterday, an 11-mile stretch of Nevada highway was shut down over the weekend specifically for Koenigsegg's pursuit of taking down the previous record holders, the Bugatti Veyron Super Sport (269.86 mph), which was later beaten by the Hennessey Venom GT (270.49mph). With factory driver Niklas Lilja behind the wheel, the Agera RS recorded a two-way average speed of 277.9 mph.

Its clocked top speed was 284.55 mph, a new world record. The original plan was for the Agera RS to make several top speed attempts throughout the weekend, as the highway was reserved for Saturday and Sunday. As it turns out, just one day was needed to accomplish the mission.

The Agera RS used for the test is a customer car with a total of 1,360 hp and 1,011 lb-ft of torque thanks to the one-megawatt upgrade. In addition to the new top speed world record for a production car, this Agera RS also smashed another Bugatti's previous world record, the Chiron's 0-249-0 mph time of 41.96 seconds. The Agera RS did it in 36.44 seconds. And, according to Top Gear's conversation with Lilja himself just after his record-breaking run, Koenigsegg isn't done setting records. Lilja hinted at the next target: the Porsche 911 GT2 RS and its Nurburgring lap time.