Porsche Stability Management has been upgraded for faster reaction times. Also, when the driver shuts PSM down, it no longer reactivates as soon as the brake pedal is depressed. Now, the driver must exceed the threshold at which the ABS will engage before PSM steps in to save the inexperienced.
For the first time, 18-inch wheels are standard on the Porsche 911 Carrera, shod with 235/40 tires in front and 265/40 rubber in the rear. There is no spare tire: instead an on-board air compressor and tire sealant allow the driver to limp the 911 to the nearest service area at speeds up to 50 mph. Brakes are cross-drilled and inner-vented all around, measuring 12.5 inches in front and 11.8 inches in back, and calibrated to provide quicker response than the 2004 model. A new variable rack-and-pinion steering system quickens the steering ratio the further off center the steering wheel is spun for better low-speed maneuverability.
In addition to more engine power, spending extra for the 2005 Porsche 911 Carrera S adds Porsche Active Suspension Management (PASM), upgraded brakes with red-painted calipers, bigger wheels and tires, bi-Xenon headlights, a multi-function steering wheel, simulated aluminum interior trim, and a silver decklid logo. Carrera S models also have round dual exhaust outlets rather than the ovals on the base car. Inside, the gauges have aluminum, rather than black, faces, and the engine cover is painted silver.