The Mulsanne's body cloaks an entirely new chassis for a Bentley. It consists of double wishbones at the front and a multi-link system at the rear. The body is suspended via an adaptable air suspension system that allows the car to lower its ride height at speed and maintain good body control and level suspension irrespective of load.
The Mulsanne’s powertrain is a totally refreshed version of Bentley’s 6.75-litre twin-turbocharged V8, now producing 505bhp and 752lb ft of torque. Other engines were considered, Bentley says, but dismissed because they wouldn’t produce the effortless low-rev torque that owners of grand Bentleys expect.
However, the technical update includes variable phasing of the single camshaft, cylinder deactivation to make it a V4 under light load, and lightweight pistons, conrods and crankshaft. It's a direct descendant of the original Rolls-Royce Bentley V8 of 1959, but today's engine could idle on the old one's unburnt exhaust hydrocarbons alone.
The engine is partnered with the very latest eight-speed automatic gearbox from specialist ZF. Its use means Bentley’s flagship model has gone from four forward speeds (in the old Arnage Red Label) to twice that number in less than a decade.
Despite its bulk – an almost naval 2745kg, 160kg more than Bentley’s claim – our test Mulsanne recorded a 5.7sec two-way average sprint to 60mph and needed only 13.7sec to crack 100mph. That’s slightly slower than Bentley’s claims, and slower still than the Ghost, but it’s by no means slow in outright terms. This near-three-tonne limousine is still faster than our 2008 road test Mitsubishi Evo X.
Bentley’s titanic pushrod V8 is the reason why. Despite tracing its ancestry back to 1952, it feels wonderful under the long prow of the Mulsanne: refined, potent, still as industrious and idiosyncratic to listen to as ever and, at last, perfectly matched with a modern gearbox. Although very hushed at idle, you get a taste of the engine’s distant savagery when you blip the throttle out of gear. The crankshaft zaps beyond 3500rpm in an instant, and with enough force to rock the substantial Mulsanne laterally on its suspension.
In gear, the twin-turbo V8 provides huge, lag-free urge, enough to make the car feel very brisk when given its head. The engine only revs to 4500rpm, but the ZF gearbox juggles ratios so judiciously that flexibility is never in question. All you get is instant and considerable performance, in whichever of the car’s six intermediate gear ratios is best chosen to deliver it.