Bentley’s 2010 Continental GTC Speed belongs to that rare class of vehicles to which the standard array of automotive superlatives simply does not apply. After all, how can one adequately convey the sensation of accelerating a 5500-pound, leather-clad convertible from rest to 60 mph in a mere 4.52seconds? Of hitting 195 mph with the top down. Of returning to a standstill via the world’s largest production automobile brakes-eight-piston calipers and 16.5-inch carbon-ceramic discs?

Though essentially a performance variant of the Continental GTC convertible, the Speed is not some stripped-down racer. Sure, it has drilled aluminum pedals, but there is no stereo delete option here. Bentley went the other direction and serves up an 1100-watt Naim audio system — the most powerful available in any production car. The knurled-chrome and leather-paneled gearshift lever of the six-speed ZF transmission further indicate a focus on fine motoring as well as high performance. So, do the turned aluminum fascias and use of 12 quilted cowhides to line the sumptuous four-passenger cocoon.

Set atop exclusive 20-inch wheels and 275/35 Pirelli PZeros, the Speed just manages to out sleek the GTC. “Speed” appears only on the doorsills while other signs of the beast — the crackle-black-finished intake manifold, dark-tinted front grille, larger-diameter tailpipes, and rear spoiler — are deviously subtle. Such subtlety evaporates at full throttle. By incorporating new pistons, lighter con rods, and a new crankcase design, Crewe engineers were able to coax 9-percent more horses and 15-percent more torque from the 6.0-liter, twin-turbo V-12 engine while reducing carbon dioxide output by 3.5 percent. This brings output to 600 horses and 553 pound-feet of torque, nearly as breathtaking as the burly wuffle of the tuned exhaust.

With communicative steering and four-way-adjustable air suspension, this all-wheel-drive heavyweight ducks and weaves like the World’s Greatest. The Bentley Continental GTC Speed will be distinguished from the standard GTC convertible by its dark tinted grille and 20-inch wheels, featuring a unique dual-thin spoke design and ultra-high-performance Pirelli PZero tires. The Speed has a lower ride height, larger dual exhaust tips and a rear lip spoiler. Both GTCs will feature a revised nose for 2010, with a squarer, more upright grille in the classic Bentley mode, as well as larger lower air intakes and chrome headlight bezels.

Like the other Speed models, the GTC Speed will be equipped with an upgraded version of Bentley’s twin-turbo, 6.0-liter W12 engine. This W configuration uses four banks of three cylinders, as opposed to two banks of six in a V12. It generates 600 horsepower and 553 pound-feet of torque, or 48 hp and 74 lb-ft more than the standard GTC. The Speed shares the GTC’s six-speed ZF automatic transmission and full-time all-wheel drive.

The result of the horsepower upgrade is Bentley’s most powerful (and fastest) convertible to date. The company promises 0-60 mph sprints in 4.5 seconds and a top speed of 195 mph with the retracting roof open. If that is not fast enough, the GTC Speed will reach 200 mph with its roof closed.

Its stability control system will allow the tires to slide a bit more before the electronics intervene in an effort to straighten the car’s trajectory, just in case the Speed owner wants to try his or her car on a track.

Carbon-ceramic brakes trim weight and improve fade resistance, and Bentley claims they are the largest on any passenger car in the world. Adaptive Cruise Control system will use long-range radar to manage speed, controlling both brakes and throttle to maintain a driver-determined time gap between the GTC and cars ahead.