Bentley's Continental Flying Spur is the fastest drawing room on four wheels
You might think driving at 274km/h on a public road in a twin-turbocharged, leather-lined supercar across the world's poorest continent would feel pretty strange.
Having done just that, during high-speed testing of a prototype Bentley in South Africa, I admit one thing felt odd - that the supercar was a four-door limousine.
That speed would be good enough to put Bentley's new Continental Flying Spur, sister to the GT coupe, among the world's fastest super-saloons - Bentley's Arnage T (270km/h) and Maserati's Quattroporte (275km/h).
But we were only pausing at 274km/h. Today's schedule called for stability testing on standard tyre pressures. Pump up the tyres and the Flying Spur can step confidently on to the top rung as the fastest four-door car in the world, at a claimed 306km/h.
The Continental Flying Spur was officially launched at the Geneva Motor Show on March 3. The car should be available in Hong Kong by the end of the year at a cost of about $3 million.
The price is remarkable in two ways: it is a gobsmacking sum of money to find under a tree; and it is the same price as the four-door's mechanical twin, the Continental GT coupe.
The two cars share their awesome, 6-litre, 552bhp W12 engine, six-speed Tiptronic transmission, four-wheel drive and the biggest braking package of any production car.
The saloon is almost 5.8cm longer overall and sits on a wheelbase 32cm longer than the coupe. To put this in perspective: at 5.3 metres overall, the 'mid-sized' Bentley is about 10.1cm longer than the long-wheelbase BMW 760Li and Mercedes-Benz S600L - and only 10.1cm shorter than the Arnage T.
The effect of the longer wheelbase has been to completely transform the four-door's interior, at least as seen from the rear seat.
In the back seat, passengers can recline in leggy Bentley luxury in comparison to the GT coupe's child-sized rear cabin.
The rear cabin can be ordered with a three-seater bench or a pair of sculpted, reclining buckets separated by a timber console.
Up front, however, it is all GT. The instrument panel is a straight carry-over, complete with stylish swoops of lavish leather and handcrafted timber.
Aside from a more upright windscreen, better all-round visibility and more space between toupee and tailored leather headlining, one could well be at the wheel of the coupe.
The weight of the GT coupe, 2,385kg, has drawn criticism, it is already a quarter of a tonne heavier than Mercedes-Benz's S600L saloon. The four-seater Flying Spur was never going to be any lighter, but to its credit the increase has been kept to just 90kg, given the new cavernous rear cabin and extra architecture.
The mighty, twin-turbocharged W12s 650Nm torque output would have impressed in the past, but not when the aforementioned Mercedes-Benz V12 can pull almost a quarter more and the Arnage T over a third more.
Minor engine recalibration was aimed solely at maintaining emissions performance, while a more perceptible change is the return to the transmission's shift points for more relaxed downshifting.
'Relaxed' is a relative term. The Spur does not dally on its way to its top speed, reaching 100km/h from standstill in 4.9 seconds (just two-tenths of a second slower than the GT) and on to 160km/h in 11.3 seconds (compared with 11.25 seconds).
It was more relevant in South Africa that, when presented with an overtaking opportunity such as a 20km straight at 240km/h, there is always a generous surge of acceleration waiting underfoot.
Throttle responsiveness even at those speeds is still exaggerated enough to betray the engine's force-feeding and it is perfectly complemented by the six-speed auto's effortless kick-down.
Make no mistake, this is one of the world's best automatic transmissions.
As in the coupe, the saloon's self-levelling, air-suspension system is adjustable for comfort and sport settings, and lowers the ride height at speed.
Bentley's four-door engineering team have been travelling to South Africa for the past two years to answer questions such as 'when?', 'how much?' and 'how quickly?'.
'At 245km/h, we drop the front of the car 15mm, so it takes on a different angle of attack. Once you get to that point, [we're] making sure that as you come up to it, you don't feel any changes in the steering or handling,' Bentley chassis, powertrain and motorsport director Brian Gush says.
'You can record all of that, but our job is to make sure that you don't notice it.'
Mr Gush, an expatriate South African, four-door project chief Cameron Paterson and engineering board member Ulrich Eichhorn were in South Africa on a high-speed mission. They had little more than 24 hours to assess the Spur's high-speed performance and feedback.
At speeds sufficient to get 370 tonnes of Boeing 747 off the deck, the Bentley's firm, squatting stability is amazing. The four-door GT feels much tighter, sleeker, more squat and confident than the galloping, 'Orient Express' immensity of the Arnage T.
While the high-speed ride found the balance between comfort and confidence, the ripply low-speed ride still needed refinement.
An area still under discussion is the high-speed steering feel and feedback. More relaxed and forgiving than the Continental GT at the straight-ahead position, it also bobbed gently over surface contours.
Dr Eichhorn is making this problem his pet project. 'One of the tasks that we had was to get a freer-feeling steering, less friction, more easily coming away from centre, to give better connection, better feedback. On this car - and we haven't found this before - it's a bit too free.'
He says the steering revisions, via revised valving in the system's hydraulics, will be gradually introduced to the GT coupe.
As for stopping from maximum speed, Dr Eichhorn knows there is no need for change. He originally signed off the identical package for the Continental GT after performing 10 consecutive panic stops from 306km/h.
Engine: twin-turbocharged six-litre W12
Power: 551bhp @ 6100rpm
Torque: 650Nm @ 1,600rpm
Transmission: ZF six-speed Tiptronic automatic
Acceleration: 0-100km/h in five seconds
Top speed: 306km/h