A Swedish supercar has broken Bugatti’s record to become the fastest ever production car.

The Koenigsegg Agera RS topped 284.5mph during a run on a Nevada highway – specially closed for the occasion – over the weekend.

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Across two runs in opposite directions, the car recorded an average top speed of 277.9mph, taking it past the previous record of 267.8mph set by a Bugatti Veyron Super Sport in 2010.

The record is yet to be officially verified, but footage appears to show the speeds confirmed by Racelogic’s VBOX, a sensor widely used for measuring vehicles’ velocity.

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Driver Niklas Lilja told TopGear.com he “wasn’t nervous” during the run, adding: “Driving the road at 100mph, it was very quiet and smooth. But at 280mph plus, it’s really quite bumpy.”

On the first of its two runs, the Agera hit 271.2mph despite driving slightly uphill and into a headwind.

That in itself was enough to beat the previous highest recorded top speed of 270.5mph, by a Hennessey Venom GT in 2014.

The Venom never officially held the record because it only did a single run in one direction.

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