2008 Porsche 911 Carrera Coupe 4

The 911 Carrera 4 has the same 325-horsepower flat-six engine as the regular Carrera but benefits from the addition of Porsche's intelligent all-wheel drive.

This system transfers at least five percent of torque to the front wheels at all times and, under low-grip conditions, can transfer up to 40 percent. So the 911 remains a nimble, predominantly rear-drive sports car but with the bonus traction of four driven wheels.

Porsche says that under daily driving conditions the average split of torque between the rear and front axles is 65/35, so the system is often at work.

A side benefit, Porsche Stability Management with traction control comes standard and helps to reduce stopping distances. PSM works in conjunction with the Carrera 4's variable differential.

As stated, powering these four wheels, which are standard size 18-inch alloys, is a 3.6 liter flat six-cylinder with 325 horsepower at 6,800 rpm and 274 pound-feet of torque starting at 4,250 rpm. It features a lightweight alloy design and Porsche's VarioCam Plus variable-valve technology.

The standard transmission is a close-ratio six-speed manual, with a Tiptronic S five-speed automatic as optional. The Tiptronic S has steering wheel-mounted controls for when the driver is in a shift-it-yourself mood.

Acceleration from zero to 60 mph happens in 4.9 seconds for the manual and 0.4 of a second longer, at 5.3 seconds, for the automatic.

Ceramic composite brakes are optional and work great for high-performance braking situations.

Other options include parking-assist sensors, self-dimming rearview mirrors, aluminum-look interior trim, a navigation system, high-end Bose audio system and six-disc CD changer.

On the 911's tail is a hidden spoiler that pops up when necessary to apply down force on the rear at high speeds and keep the car firmly planted on the road.