Bentley is showcasing its 2010 Continental GT Convertible GTC) throughout the country this spring, and last week was Bellevue’s turn as the automaker brought its fastest machine to the local Eastside dealership for test drives.

The new car has only a few aesthetic differences from its predecessor, like minor grille changes, optional 20-inch speed wheels, a rear spoiler, chrome surrounds on the headlamps, and larger, rifled exhaust tips.

A more noticeable difference is what’s under the hood with the 6-litre, 12-cylinder, turbo-charged engine that delivers 600 horsepower and a sense of unceasing acceleration.

The new GTC boasts a top speed of over 200 miles per hour and a zero-to-sixty time of 4.5 seconds.

“This is the fastest, most powerful Bentley convertible ever,” said Bentley Bellevue sales executive Michael Shaffer.

The older GTC put out 552 horses and topped out at 195 miles per hour, clocking in with a zero-to-sixty time of 4.8 seconds.

New fade-resistant brakes coupled with the car’s electronic stability-control system help give the ride smooth handling, while the exhaust has a predatory sound that lets people know what kind of vehicle they’re dealing with.

Changes to the interior include diamond-quilted leather seats and a knurled shifter, both of which add to the car’s refined look. The inside also features wood-veneer or optional aluminum-veneer surfaces and so much smooth leather front-to-back that the vehicle smells like a brand-new baseball glove, even with the roof down.

The 2010 GTC also features a new Naim audio system with 14 speakers and a 150 x 225 millimeter sub-woofer backed by an 1,100-watt amplifier.

Also new is the automatic cruise-control feature that allows drivers to set a distance between themselves and the next vehicle rather than simply fixing their speed.

The 2010 GTC will be available starting August with a base price of around $231,000.