Bentley Continental GTC: Smooth operator

Following in the slipstream of the Azure, Bentley is releasing another convertible. John Simister gets to grips with the GTC

The Bentley boys design another winner

A new Bentley convertible. Didn't we read about such a car just a couple of months ago? We did - it was the Arnage-based Azure - but this is something else again. Two new convertibles in as many months is a remarkable occurrence, but really it's just an accident of product plan.

The Azure belongs to the dinosaur class of Bentleys, where mass and magnificence rule. The new Continental GTC, however, is the latest issue of the modern family of densely engineered, hi-tech, slightly less vast Bentleys created within the deep pool of Volkswagen Group expertise.

These cars have four-wheel drive and 6.0-litre, twin-turbo W12 engines evolved from the Volkswagen Phaeton's powertrain, and there's little wrong with that.

The Phaeton is an admirable and misunderstood car that sells in scant quantities; the fact is, there are many more British-built Bentley W12 engines on the road than German-built Phaeton or Audi A8 ones. In fact, Bentley makes more 12-cylinder engines than any other car company.

The GTC is fairly obviously based on the steel-roofed GT, but there is more to it than just a soft-top conversion. I discovered this for myself as I threaded its two-and-a-half-tonne mass along the mountain roads near Aspen, Colorado - the sort of place many a Bentley export is likely to end up. Previous Continentals have been a little short of satisfaction in the way they steer, and the Flying Spur saloon I drove recently had an inappropriately thumpy ride. Yet the Continental, with the biggest potential for dynamic disaster, thanks to the removal of its rigidity-giving roof, is currently the best of the lot.

Picture the scene: the roof is down, we're 12,000 feet above sea level, the Factor 50 is working overtime. The air is thin - thin enough for your lungs to run out of puff by the time you have walked from one end of the GTC to the other. But turbochargers can compensate for thin air by blowing harder, and the only difference you might notice is an increased delay between pressing the accelerator and feeling the result.

But when you feel it, it's extraordinary. There's more power here - 560bhp - than even the giant Arnage T possesses, and even if the pulling power is less gargantuan at 479lb ft (available at just 1,600rpm), it's still more than "adequate", as Bentley and Rolls-Royce were once apt to say. Especially as this lower pulling power is offset by the engine's much broader rev range, making it a brilliantly flexible source of thrust.

That such a weighty car can reach 60mph in 4.8 seconds makes you fear for the integrity of its mechanical components. You had better make sure there's lots of greenery nearby, too, to absorb the carbon dioxide. The facts and figures become yet more surreal when you learn that this elegant but not visually racy convertible can reach 195mph - albeit not in Colorado, given that the police carry guns.

Even harder to credit is that the GTC will still touch 190 with the roof down, at which point, says engineering director Ulrich Eichhorn, there's no buffeting, even for rear passengers, because the draught vortex has moved behind the cabin. Test drivers during the GTC's development were advised not to poke their fingers above the windscreen at that speed if they intended to keep them.

With the roof up, the GTC really is as serene as a saloon, such is the sealing around the windows and the sound absorption of the hood's seven layers. There's even a reading light above the rear window. The folding-down of the roof takes 25 seconds - any less and the movement would lose its grace, says Dr Eichhorn - and you can perform this task with the car moving at up to 20mph.

Once stowed, the GTC looks rather shapelier than the big-bottomed coupé-cabriolets at the other end of the automotive food chain. That's because the hood is stowed within the rear body's natural shape, such is the flexibility and compressibility of fabric compared with metal.

The rear air suspension had to be modified to allow this, but it has done no harm. Which brings me to the most surprising aspect of the GTC: it has the smoothest, most accurate and most natural-feeling steering of the whole Continental range, and it rides over bumps with the greatest serenity. Yet it also grips with determination, and the way the four-wheel drive hauls this monster roadster out of a corner, exhaust-silencer bypasses open and 12 cylinders singing their deep and surprisingly vocal chorus, is hard to believe at first.

How can this be? The sound effects are simple: they have been tuned to sound better to benefit the open-air ear, but only when the GTC is being driven with gusto. The ride and handling are the result of a structure far stiffer than a big convertible has any right to have, made so by mounting the suspension subframes rigidly to the structure instead of via rubber interlayers, and bracing the subframes to the sills. You'd expect that to destroy the refinement of the ride, but revised rubber bushings in the suspension fix that.

Also, our GTC was running on 19-inch wheels - vital, says Dr Eichhorn, for a good ride in any Continental. That Flying Spur I drove thudded over sharp bumps because it was on 20-inch wheels. So - as ever - don't assume big wheels are better, however good they might look.

This is a remarkable convertible with an exquisite interior, a well-judged blend of trad Bentley and modern technology with not a component in sight that looks made of something it isn't.

If there's a fault, it's only that the GTC's six-speed automatic gearbox doesn't always shift as quickly as you might like, even if you use the lovely aluminium manual shifters mounted on the steering column. It's to do with handling the engine's pulling power without breaking the transmission, so fair enough.

The GTC is yours for £130,500 - but there's a waiting list at least a year long. That will give you time to fight with your conscience over the 410g/km official CO ₂ emissions figure. Not, I suspect, that it troubles the average Bentley owner overmuch.