A Serious Undertaking
Besides horsepower/torque specifications, several elements separate Impreza 2.5i, WRX, and WRX STI models. Turning the ignition key in the WRX STI tells you one difference right away, and that's the sound. Non-modified 2.5i and WRX models are quiet. Sometimes you have to strain to hear that SUBARU BOXER engine sound. But there's no doubt about what's under the hood when you crank the ignition of a WRX STI. It rumblesthat beautiful Subaru flat-four engine note.
I could tell by looking at the tires that this particular WRX STI Sedan had been involved in some major driving. Even at 3,400 miles, the tires obviously were worn, showing the signs of (over-)active steering and braking.
The WRX STI is a serious automobile – what I refer to as a "real car." It's more than transportation or a daily driver. It's more than some of its comfort and convenience amenities. Enthusiasts and fans love this car for its mechanical capabilities and what they can do with it, even if the "doing" is touring.
Along with the 305-horsepower turbocharged engine, the WRX STI has several features that evolve it from "interesting" to "serious." These have to do with driving the car, and among them are Subaru Intelligent Drive (SI-DRIVE), Driver Controlled Center Differential (DCCD), and Vehicle Dynamics Control (VDC). All of these allow driver input.
From the center console, the driver can select one of three types of performance (modes of vehicle performance characteristics) via SI-DRIVE. These are "Intelligent," "Sport," and "Sport #" (Sport Sharp). They should be named "Wild," "Hairy," and "Extreme." These settings regulate the engine control unit and electronic throttle to change the effects of throttle pressure. Throttle operation in Intelligent mode feels normal – like it would in a WRX. The Sport setting makes the engine more responsive to throttle settings, and Sport # makes the car a raging beast. I don't use the words "raging beast" lightly, and you can't take this car's capabilities lightly, either. It becomes viscious!
For example, you have to be extremely careful and alert when applying full throttle with the VDC turned off. Traction control and stability control won't be there to help you out of trouble. How do I know? I was on a test-drive. You have to try out things.
VDC can be set for three modes of operation, too. These are Standard, Off, and performance-oriented modes. Over time, a driver will find his or her comfort level with each mode.
DCCD manages the way power splits between the front and rear wheels through the center differential. A switch on the center console allows the driver to choose between a manual and three automatic modes. I was able to play with these settings on paved and gravel roads, and you can feel the difference. The closer you get to full lock, the tighter the steering feels. Making full use of the three controls will take a lot of practice to match their level of sophisticated technology with your level of driving competence. (Find more on these technologies in the Blueprint article "Tailoring the STI – VDC, DCCD, SI-DRIVE" in Version 5.1.)
Besides the controls themselves, the presence of the three technologies is reflected in their readouts in the instrument panel. The instrument panel is another area in which the 2.5i, WRX, and WRX STI differ. Instrumentation for the 2.5i follows a minimalist strategy, with a large, center-mounted speedometer and smaller tachometer gauges. The WRX switches to a larger, center-mounted tachometer and smaller speedometer, as well as adding an engine-temperature gauge. The WRX STI has unique markings on its center-mounted tachometer and smaller speedometer, plus it has indicators for DCCD, SI-DRIVE, and two-part lights for VDC.
Across the dashboard, even the trim surrounding the driver and front passenger reflects the difference between models. The 2.5i and WRX have dark gray trim set in the otherwise black dash. Trim in the WRX STI is black.
Also note that the view out the rear window is hardly obscured by the spoiler. Instead, the spoiler frames the view of the road behind.