Porsche has unveiled the facelifted 911 Turbo and 911 Turbo S ahead of the North American International Auto Show.

Looking instantly recognizable, the facelifted models have a new front fascia with revised air intakes and new LED day time running lights.  A closer inspection also reveals new door handles, updated taillights, and restyled 20-inch alloy wheels.  Rounding out the styling changes are a new engine cover and a modestly revised rear bumper.

The interior largely carries over but designers add a new sport steering wheel with a rotary mode selector that has Normal, Sport, Sport Plus, and Individual settings.  Drivers will also find an upgraded Porsche Communication Management system and a standard Bose audio system.

The cars feature a standard Sport Chrono Package that includes a new Sport Response button that "preconditions the engine and gearbox for the best possible responsiveness at the push of a button."  When pushed, the button provides "optimal acceleration" for up to 20 seconds.

Speaking of performance, there's a new PSM Sport Mode button that alters the intervention threshold of the Porsche Stability Management system.  Porsche says the mode enables drivers to approach the car's limits even more closely than before.

Both models are powered by a twin-turbo 3.8-liter six-cylinder engine that develops an additional 20 PS (15 kW).  This brings the total output of the 911 Turbo to 540 PS (397 kW), while the 911 Turbo S climbs to 580 PS (427 kW). 

Thanks to the extra power, the Turbo accelerates from 0-100 km/h in 3.0 seconds before hitting an increased top speed of 320 km/h (198 mph). Likewise, the Turbo S rockets from 0-100 km/h in 2.9 seconds before topping out at 330 km/h (205 mph).

Despite being faster and more powerful, Porsche was able to reduce the fuel consumption of all variants by 0.6 L/100km. Porsche credits this to a revised engine management system and an upgraded transmission with new gear change mappings.

The Porsche 911 Turbo family will go on sale in Germany in late January and pricing starts at €174,669.

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