Bentley ups the ante with its titanically powerful Mulsanne Speed

In the back seat of the new Bentley Mulsanne Speed, thoughts of precision engineering, engine management, throttle response and brake horsepower are almost entirely irrelevant. You're more likely to be fiddling with the silky smooth mechanism that raises the integrated keyboard and iPad dock from its position in rear of the front seat, or watching the glass fridge door glide open at the push of a button in order to retrieve the elegant Bentley-designed champagne flutes. Or you could be flicking through the massage programmes in the twin reclining seats or just simply marvelling at the sheer level of craftsmanship and quality that has gone into every single visible surface.

In fact, should the driver attempt to harness even a fraction of the available power, the resulting surge in velocity might make your finger slip on the keyboard or, heaven forbid, a little champagne spill onto the quilted leather upholstery. Instead, you hope for sedate, leisurely progress in what could be described as the fastest executive suite on earth, a worthy companion to a Falcon 500 or a Riva Mythos.

The new Mulsanne Speed is a refined and streamlined version of Bentley's flagship saloon. As its name suggests, the Speed adds rather more zing to what was already a titanically powerful car, bringing yet more refinement to its venerable V8 engine and adding subtle styling tweaks that'll up the ante on the five star forecourts this car is designed to frequent. The company claims the Mulsanne Speed will be favoured by owner-drivers, a relatively rare breed at this end of the market. Behind the wheel there's no lapse in creature comforts, and the car starts, stops and steers like a machine a fraction of its (considerable) weight.

That's largely down to the 530hp put out by the V8, converted into vast reserves of torque to maintain that creamy, effortless power delivery that characterises the brand. If the champagne flutes are empty and the road ahead is clear, the Speed will blast to sixty miles an hour in less than five seconds, topping out at around 190mph. We saw a shade under 170mph until we ran out of runway - even Florida's abandoned Everglades Jetport didn't have the space to accommodate all this car can do. 

The V8 has its origins in an engine designed in the early 1950s, although it has evolved beyond all recognition. In fact, the company asserts that the emissions from the original could probably be used to power the latest version (although they haven't tested this hypothesis just yet, perhaps mindful of drawing attention to the new car's still rather unspectacular statistics).

The hefty saloon has always been the acme of automotive ambition, but that could be changing. In 2015, Bentley will finally unveil the SUV it has been tinkering with the past few years. In the meantime, Range Rover has stolen a march on the market, pushing its flagship model further and further into the realm of super-luxury - a new stretched version designed in collaboration with Holland and Holland is available for around £180,000. Even Rolls-Royce is rumoured to be mulling over a 4x4.

On the other hand, Bentley has also just unveiled the Grand Convertible (opens in new tab), a conceptual variant of the Mulsanne with two doors and vast, mahogany swathed open deck. It's beautiful, striking and extremely desirable, implying that some traditional forms will stay aloft for a while yet at the very top of the industry.