"Run the 1,000 hp Bugatti Veyron Grand Sport at top speed and it will empty its 26.4-gallon fuel tank in 12 minutes. The Vitesse, with its extra 200 hp, will do it in 10.3, which is lucky actually because Michelin won't guarantee the tires to run above 250 mph for more than 15 minutes." Bugatti's chief vehicle engineer, Jens Schulenburg, can't help but chuckle as he tells us about his latest project, and who can blame him when the Vitesse's spec sheet is littered with such ridiculous numbers.

Essentially an upgraded version of the open-top Grand Sport, the Vitesse's engine comes from the now sold-out Super Sport coupe. That means four larger turbochargers, an extra 200 hp, and performance to make your knees quiver. Top speed is 255 mph with the roof panel in place, or a breezy 233 mph with it removed. Bury your right foot and 0-186 mph takes 16 seconds, slam on the 15.74-inch carbon-ceramic brakes and you'll screech to a stop 7.9 seconds later.

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The 0-60 mph time of 2.5 seconds tells a different story though. It's actually 0.1 seconds slower than the less powerful Grand Sport -- you can blame the bigger turbos taking longer to fill their lungs for that. And there is a noticeable delay between squeezing the gas and the turbos lighting up at 4,000 rpm -- a gentle pause that gives you just enough time to brace you internal organs and flex your face muscles before they're both rearranged.

It's not the slug of acceleration that shocks so much as the way it snaps you back in your seat and keeps you there until you lift off. At that point the four turbos open their waste gates and emit an almighty hiss millimetres behind your head. With most convertibles the loss of the roof brings you closer to the action, in the Vitesse it sounds like you're wedged between the banks of cylinders with every whistle, pop, and roar mainlined into your ear. If a Ferrari V-12 is a banshee, this engine is an ogre with an appetite for super-unleaded.

So it sounds brutal and accelerates like nothing else, but the Vitesse's real home turf is at high-speeds. We managed to hit 205 mph on a closed test track before having to brake for the next bend, and the car was feeling more stable by the second, while the cylinders were only just hitting their stride. Thanks to a newly designed wind deflector that clips to the top of the windscreen, the high speed run was a noisy but not windy experience.

The real surprise comes when you discover the Vitesse is not merely a straight-line dragster in a carbon-fibre dress; there's a genuine delicacy to the way it handles. Despite weighing almost 4400 lbs and power being sent to all four wheels, the steering is light and weights up nicely as the angle increases. Carry too much speed and you'll wash wide with understeer, don't get on the gas early enough and the turbos won't be spinning when you need them. Time it right though and you can carve deliciously clean arcs through the bends, jump on the throttle at the apex and storm down the next straight leaving the world in your wake.

There's one problem with driving the Veyron on public roads though, and it's not losing your license -- it's losing any part of the bodywork. Driving something this wide, worth more than a mansion, on roads packed with careless drivers coming the other way certainly focuses the mind -- and not in a good way.

The second surprise came as we trundled through town back to the hotel -- the Vitesse is a pussycat at low-speeds. New softer springs and dampers have been fitted, but with stronger anti-roll bars, and the result is a supercar that deals well with even the worst surfaces. It's at crawling pace that you recognize what a masterpiece this gearbox is, too.

Built by British firm Ricardo especially for the Veyron, the seven-speed twin-clutch 'box costs Bugatti nearly $80,000 a pop -- and was the major engineering hurdle in this car's development. The result is that on full bore upshifts it slams home the next ratio without a break in torque, while in auto mode, at sedate speeds, it slurs them perfectly. Only the occasional jerk as you pull away reminds you this isn't a conventional torque converter.

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Strip the Vitesse down to its components and the attention to detail is beyond belief. Poke your head through the 20-inch rims (if it were possible) and you'd notice small scoops of metal missing from the back of each spoke -- that saves 1.1 pounds per corner. If you're caught in a downpour, a temporary umbrella lives under the hood and fits snugly over the cabin. Even the airbag mechanism is mounted on a spring inside the steering wheel to damp any vibrations before they reach your fingertips.

With such a broad set of circumstances to cover, three driving modes prepare the car for a variety of situations. In town traffic and up to speeds of 112 mph there's the default setting. Hit a button next to the gearlever though (or it will switch automatically above 112mph) and you enter Handling mode -- here the suspension squats down by 35mm and 20mm at the front and rear respectively, the rear spoiler deploys and flaps in the front diffuser open up.

If you find somewhere expansive enough to make an assault on the top speed however, you'll need a separate key that when turned sinks the suspension (by a further 15mm at the front and 25mm at the rear) as well as retracting the spoiler and performing a series of checks on the car's vital statistic to ensure it's up to the task.

The question then is whether any car can really be worth the ludicrous $2.5 million asking price. No, of course not, nothing on four wheels is, but the Vitesse is the most talented and dramatic incarnation of the Veyron so far. And for those with the means the Vitesse does something no other car can claim -- it takes an ocean of power and manages to tame it into a package that's as useable around town as it is beyond 200 mph. Life will always seem a little slower from now on.

2013 Bugatti Veyron 16.4 Grand Sport Vitesse