2005 Subaru Impreza WRX STi and Mitsubishi Lancer Evolution MR Road Course Test

Road Course
Dissecting performance into neat little packages is one thing, and putting it all together on a track is another. We wanted to see how these two track-ready sedans use all their tricks in a best-of-three-laps showdown. Familiarization and cool-down laps didn't count. We often use the Streets of Willow racetrack and find it a particularly technical course that rewards control over horsepower and grip over grunt.

Lapping the STi feels a lot like lapping a rear-drive car without the threat of massive on/off-throttle oversteer. Once the car has found its maximum grip in a corner (and begins to hint at understeer), a brief throttle lift induces a nearly imperceptible yet useful amount of oversteer where the nose of the car tucks nicely into the corner. Compared with a 2004, steering feel in the STi is more responsive, less jittery, and produces no bump steer. The STi's herculean brakes' ultimate abilities haven't changed, but they now offer better feedback and a firmer pedal, going deep into corners where skidmarks reveal the overconfidence of others.

Click on image above to view the Willow Springs Road Course Chart. The mph rollercoaster ride at the Streets of Willow Springs: Top graph shows each car's best effort (overlayed); below is the amount by which the Mitsubishi would gradually pull ahead of the Subaru if they were to have started these laps together.

The STi's new front differential provides even more controlled traction on corner exits while the six-position-adjustable center differential continues to offer a wide range of front/rear bias options for putting the power down. Subaru's all-wheel-drive system uses an open planetary center differential with a rear-drive bias (35 percent front, 65 rear). An electronically operated hydraulic clutch can progressively lock this differential automatically or manually. When fully locked, the torque split is 50/50. The differential apportions torque based on throttle position, cornering force, acceleration or deceleration rates, and wheelslip. In manual mode, the Subaru driver can vary the front/rear torque bias with a turn of the six-position adjuster wheel between the seats from the normal 35/65 to the opposite 65/35 or lock it. We found it made the best lap times left in Auto mode.

Running laps in the Mitsubishi is a point-and-shoot exercise punctuated by a drift here and a slide there. In max-grip corners, we discovered there's not much a driver can do to change the car's preordained trajectory. Once it reaches the point where understeer begins, the only way out the other side is through patience. More gas, more steering, or even left-foot braking don't help. Luckily, the Mitsu was going extremely fast in those critical corners.