Photos: 2008 Subaru Impreza WRX STI

The STI can be exhilarating or frustrating, depending on how you use it. With the engine speed above 4,000rpms on a winding road, it is fantastic, but 10 mph stop-and-go traffic is a teeth-grinding experience.

While the STI's grille presents a subtle band bookended by the high-intensity discharge headlights, the big scoop on the hood suggests its power.

The engine compartment is packed with a 2.5-liter four-cylinder boxer style engine, force-fed by an intercooled turbo system. It produces 305 horsepower way up at 6,000rpm.

With its curved hatchback, we think the STI resembles a blister. Subaru doesn't offer an STI in a sedan body.

The STI gets a few cues that set it apart from the standard WRX hatchback, such as the front and rear STI badges.

The fenders gain some flair with the STI version, along with these vents to bleed heat from the big performance Brembro brake system.

As a hatchback, the STI offers a practical and easily accessible cargo area. But we can't imagine filling it with groceries. With the STI, it's more suitable for spare tires and extra fuel tanks.

The STI gets LED taillights along with its standard high-intensity discharge headlights.

The interior of the STI is very similar to that of the WRX, except for the STI badges and a few extra controls.

The STI's handling is superb and requires a lot of input from the driver. A little bit of understeer gives the driver a lot to work in cornering, suitable for dirt and gravel driving where oversteer could be disastrous.

The STI has an information pod at the top of the stack, which shows the time and fuel economy, and a double DIN stereo head unit that could be easily replaced by something with more features.

We like that the STI gets a sixth gear, where the standard WRX only has five. But most of the real work is done in second and third.

Most Subarus have the SI drive feature now, but the STI also gets an adjustable center differential to complement the two limited slip differentials fore and aft.

The SI drive has three modes: Intelligent, Sport, and Sport Sharp. Intelligent mode offers slow throttle response but should save some gas.

Here you can see the car is in Sport Sharp mode, which gives the quickest throttle response. The center differential is in automatic mode. In automatic, the car will adjust the center differential slip based on various sensors.

You can bias the automatic center diff mode by pushing the control lever on the console up or down. If it is biased toward more slip, the car will behave better on dry, paved surfaces.

Biasing the center diff for more lock lets the car handle slippery surfaces better, as it will keep torque distributed more evenly between the front and rear axles.

In manual mode, you can push the control lever up to completely lock the center differential, allowing no slip, a setting appropriate for mud, slush, and gravel.

You can also maximize the center slip in manual mode, which will give the car better control during cornering on dry surfaces.

The stock stereo plays MP3 CDs in its six-disc changer, but doesn't show ID3 tag information. It does display file and folder names.

We weren't impressed with the audio quality or the audio system's power. At 80 watts, we had to turn it way up to hear anything.

There is a convenient auxiliary input jack for the stereo in the center console.