There are several remarkable things about Koenigsegg's record-breaking run in its Agera RS. One is that the firm attempted it on a public highway. Yes, it was clearly a dead straight (and presumably level) section of closed road in Nevada - but it remains an open and unsecured piece of tarmac, with all the usual vagaries of surfacing and camber and wildlife.
Then there's the 'standard' rubber. You'd hesitate to call Michelin's Pilot Sport Cup 2 tyres 'stock' given their capability, nevertheless they are still Y rated - which means that the manufacturer guarantees them up to 186mph; quite some way from 277.9mph.
Of course the Agera RS went slightly faster than that. It hit 284.3 mph in one direction. Then 272mph coming the other way. The factory driver, one Niklas Lilja, takes full advantage of his 11-mile route, too - as seen in the video, the rolling start is as gentle could be; with the full force of Koenigsegg's 5.0-litre twin-turbocharged V8 apparently not indulged until around 175mph.
Remarkable stuff. Not least for the 1,360hp and 1,011lb ft of torque making its way to the rear wheels at high crank speeds, in a car which reportedly weighs 1,360kg - a power-to-weight ratio that makes the Bugatti Veyron 16.4 Super Sport (its vanquished foe) look decidedly undernourished.
That said, there's no official word yet confirming the Agera RS's succession to the fastest production car title; there is only the in-car evidence - supplied by Racelogic - of Saturday's run. Even without Guinness's approval, it's an astonishing effort, and following the model's 0-400-0 (unofficial) triumph last month, surely confirms the Koenigsegg as the world's fastest car. For now.