Koenigsegg Agera RS is officially the world's fastest production car

Koenigsegg Agera RS on Route 160 in Nevada before setting a new top speed record for a production car. (Koenigsegg Automotive)

During tests on an 11-mile stretch of Las Vegas highway the Swedish hypercar managed a remarkable average speed of 277.9 mph or 444.6 km/h.

More impressive still is that in the second of the car's speed record attempts, it actually hit 284 mph, suggesting that on the right day, with the right wind and temperature conditions, the car still has something left in the tank.

Nevertheless, the official average speed -- 277.9 mph (the car managed to hit 272 mph on its first attempt and car's speed is calculated by adding both speeds together and dividing by two), is still a significant improvement on the current official record -- 267 mph -- held by the Bugatti Veyron Super Sport.

The Supersport's replacement, the Bugatti Chiron is yet to make any official attempt to set a new top speed record. The company is waiting to see what the competition achieves before it heads out to the test track where it will have two advantages. The first is last mover advantage and the second is that the VW's test track is big enough and long enough to try and set a new record.

For its record run, Koenigsegg needed to borrow an 11-mile stretch of straight highway, and the Nevada authorities were kind enough to shut down a section of Route 160.

Likewise, Hennessey Performance has, until now, had to make do with airport runways for its speed record attempts, which, unless the car is capable of astronomical levels of off the line acceleration, are not long enough to allow a car to hit speeds close to 300mph before it's time to apply the brakes.

So even though these top speeds are essentially academic -- there is nowhere in the real world where an owner of one of these cars could conceivably come close to achieving them -- it makes for excellent high-octane entertainment for car obsessives around the globe. Traveling at 300 mph means covering a distance of 134 m a second or 8 km every minute.

At SEMA 2017 Hennessey Performance unveiled the Venom F5, which it insists is capable of a theoretical 300+ mph, and if it can find a long enough stretch of straight road and get the local authorities to close it down, it will soon be able to prove it.

But Koenigsegg isn't done yet, either. As phenomenal a car as the Agera RS is, it is not the company's current flagship model. The Regera is faster and more powerful but it is yet to hit the track. However, if Bugatti or Hennessey blitz the new record, expect to see it driving along Route 160 very shortly.