Earlier reports of a more potent version of the Panamera Turbo have proven true, following the unveiling today of the brand new 2012 Porsche Panama Turbo S. Once again, with its new top model in the Panamera model line, Porsche is raising the bar for sporty four-door cars in the luxury class by yet another notch.

As predicted, the Panamera Turbo S packs a more powerful version of the now familiar twin-turbocharged 4.8-liter V-8, with peak output now resting at 550 horsepower and 553 pound-feet of torque--up 50 horsepower and 37 pound-feet on the regular Panamera Turbo. However, hit the “Sport” or “Sport Plus” buttons on the dash and torque jumps up to 590 pound-feet momentarily.

The increased performance can be attributed to two main enhancements: Improved turbochargers with titanium-aluminum turbine wheels and a modified ECU. The use of the titanium-aluminum alloy reduces the weight of the turbine and compressor wheel, resulting in a lower moment of inertia and thus in improved and more agile engine responsiveness.

Thanks to an updated Launch Control function, the 0-60 mph dash is completed in just 3.6 seconds and top speed rises to 190 mph. Despite the increased performance, fuel consumption remains at the same level of the Panamera Turbo: an EPA rating of 15 mpg city/23 mpg highway (18 mpg combined).

Differentiating the new Panamera Turbo S from lesser models in the Panamera line are special 20-inch wheels with increased rear axle track width, custom side skirts, and an adjustable rear spoiler finished in the same color as the rest of the car.

Inside, there’s a two-tone finish for the leather trim with an exclusive black and cream look just on the Panamera Turbo S, as well as a new agate grey and cream.

The new 2012 Porsche Panamera Turbo S will go on sale in the U.S. later this spring, and will have a base price of $173,200, excluding $975 for delivery and destination.