THERE'S SOMETHING ALMOST uncanny about the way the Mulsanne Speed gathers momentum. It is, after all, a car that fully loaded weighs more than three tonnes, measures nearer six metres than five and has an interior so opulent that it would shame many super yachts. Yet stamp on the drilled-aluminium accelerator pedal – one of several discreet pointers to the Speed's enhanced performance over the “Signature” (which is Crewe-speak for standard) Mulsanne limousine – and there's a surge of energy so monumental and sustained that it verges on the terrifying.
Possibly the last in a long line of Bentleys (not to forget pre-BMW Rolls-Royces) to be powered by a 6.75-litre V8 whose basic design dates back to the late 1950s, this behemoth is a curious yet ruthlessly effective combination of the archaic and the contemporary. One of just a handful of power units currently in production that still employs pushrod-actuated valves, the Speed's venerable engine nonetheless boasts such up-to-the-minute accoutrements as cylinder deactivation, variable valve timing and a brace of turbochargers, and following major surgery to the combustion system, output has now been boosted to 530bhp. That's quite a lot of horses, but the real story is in the torque – an altogether bonkers 1,100Nm of twist, all of which is available from as little as 1,750rpm right up to 4,200. It's that which impels the Bentley towards the kind of warp-factor speeds that monsters this size really shouldn't be capable of.
The Speed moniker is an obvious reference to the marque's glory days between 1924 and 1930, when it won the Le Mans 24-hour endurance race five times with machines that were as big as they were rapid (rival Ettore Bugatti derogatorily referred to them as the “world's fastest trucks”). It equally acknowledges the assumption, however, that owners of this uprated Mulsanne will want to drive their cars as much as be driven in them.
Thus, comprehensive recalibrations to the eight-speed ZF automatic gearbox, steering, air suspension and brakes have sharpened the responses in almost every area, making Bentley's flagship limousine more assured, agile and precise at speed – and crucially far more entertaining to drive than you'd ever imagine. The transmission now features Sport mode, while inputs from throttle to dampers can be individually programmed through the drive-control system. Perhaps the only glaring omission is carbonceramic brakes, which are offered only as an option and should surely come as standard on a vehicle that's as unfeasibly large, heavy and fast as this.
Of the 1,100 or so Mulsannes built each year, the company estimates that just 300 will be Speeds, so that even assuming that production were to stretch out over the next six years, total output will likely be limited to fewer than 2,000 examples. Further emphasising its exclusivity vis-àvis lesser Mulsannes – if a car that in its most basic form costs around US$300,000 (and at least twice that in most Asian markets once tax and other price loadings have been applied) can be so described – are the range of exclusive paints with subtle contrasting undertones, the 21-inch directional wheels with cursive spokes specially handed for the vehicle's left and right sides, the dark-tinted matrix grilles and vents, and the smoked headlight and taillight glasses.
For the interior – which, like much of the rest of the car, is painstakingly put together by hand and thus can be personalised to its owners' every whim – Bentley has sought a more contemporary take on what still feels like a private club on wheels. Two-tone leather abounds on the vast chairs and doors, on which light-coloured diamond-quilted hide and matching stitching contrast with darker surrounds, as well as on the small and eminently wieldy steering wheel. Similarly, the choice of 10 wood veneers (with grains matched for each side of the cabin) now includes gleaming piano black with carbon-fibre inlays.
So much so traditional, but the Speed also bristles with up-to-minute technology, such as on-board Wi-Fi, a 60GB (though why so small?) hard drive on which to store music and videos, electrically operated rear tables that, when lowered, each reveal an iPad with matching keyboard, and an extra-cost 2,200-watt Naim stereo designed specially for the car. If all that weren't sufficient, back-seat passengers can help themselves to chilled champagne from a small cooler recessed behind the central armrest, while enjoying movies via a pair of eight-inch screens and Bluetooth headphones.
Clearly, Bentley's efforts to refashion the Mulsanne as a genuine driver's machine haven't adversely affected the passenger experience one iota, as I discover while being chauffered back through the Everglades to my Miami Beach hotel following our 250km road test through the Florida Keys, seat comfortably reclined and crystal flute of chilled bubbly in hand. But what you're most interested in, I'm guessing, is what the Mulsanne Speed is like from behind the steering wheel.
Our drive is split into two halves: a largely sedate cruise from our hotel in Bal Harbor, crossing Miami by freeway and then heading southwest across the islands and Overseas Highway towards Key West; and a series of highspeed runs at a deserted airfield in the centre of peninsular Florida, under the tutelage of motorracing legend and five-times Le Mans winner Derek Bell. The former reveals the Speed to be as effortless and supple a way of wafting above the sparkling blue waters of the Gulf of Mexico as could be hoped for, though such is the pedestrian gait of the traffic stream that we rarely have the opportunity to reach even mildly illegal velocities, let alone think about wringing the car's neck. Indeed, being restricted to a maximum of 55mph (around 90km/h) and with the engine operating on just four of its eight cylinders for most of the journey, the Bentley never even comes close to breaking a sweat.
That's more or less exactly as I expect, as opposed to the startlingly different beast that's revealed once we're flown in by helicopter to fling the Mulsanne around on a rudimentary track laid out on the aerodrome's runways and taxiways. With Bell's reassuring presence strapped in beside me, I flatten the throttle and the car's front deck rises, the monstrous torque hurling us forwards before I brake and throw it into a series of bends and straights.
Sport mode permits the engine to run up towards the red line before a higher gear is selected, though I'm holding the ratios by shifting manually with the paddles: whichever, Bentley's claimed 0-100km/h acceleration of 4.9 seconds seems in no way fanciful, such is the awesome potency of this big old motor. Perhaps even more remarkable, though, is the car's ability to change direction, thanks to the stiffened air suspension, and the reassuring feedback imparted by the slightly heavier steering. Despite its sporting aspirations no vehicle this massive could ever be considered a sports car, yet it's a hugely enjoyable thing to drive in every way and far more involving than it has any right to be.
The runway isn't long enough to put the Speed's maximum of 305km/h to the test. My flat-out run yields somewhere between 155-160mph – a smidgeon above 250km/h, in other words, and there's clearly much more to come – but even then it feels as firmly planted as if metre-deep foundations had been dug into the earth.
Of course, in an age of electricity, hybrids and downsizing, a car this magnificently dismissive of such trends is bound to be regarded as an anachronism. After my brief time with the Bentley Mulsanne Speed, however, I'm inclined to regard this glorious, big-hearted and beautifully built anomaly, which cocks a snoot at every convention, as a genuine treasure. Indeed, I'd go further and argue that with its outrageous combination of luxury and performance, it has all the makings of a modern classic.