What caused the increase from 165-horsepower in last year's Impreza to 173 now? The engine now comes standard with oil pressure actuated i-Active Valve Lift, a variable valve timing system that not only boosts

The engine now comes standard with oil pressure actuated i-Active Valve Lift. (Photo: Subaru Canada)

power at the upper edges of the rev range, but also fattens up the mid-range torque curve.

The result is a little car that hauls its tiny derriere up to highway speeds in very short order, whether mated to its standard five-speed manual transmission or a new four-speed automatic. Yes, believe it or not the vehicle class that could use 5- and 6-speed automatic transmissions most, to optimize what are often lower output engines, still makes due with four-speed automatics in every entry. This will change, no doubt, but at the time of writing a four-speed is as good as it gets. Of the lot, the torquey Impreza engine probably fares best when hooked up to its auto-box, nipping off the line with virtually no hesitation and ever willing to quickly downshift when called upon for passing purposes. It doesn't include a manual mode, per se, but as experienced while testing an automatic transmission-equipped Impreza 2.5i in and around Mont-Tremblant, Quebec, where the car was recently introduced to Canadian journalists, its gated shifter can be used for manual-like shifting quite easily.

The ACT-4 automatic, as it is called internally, features many upgrades over the outgoing transmission. Now with enhanced control logic, the transmission features Subaru Active Torque Split Multiple Plate Transfer System (no acronym possible) for distributing torque to the front and rear axles depending on driving conditions. Driving conditions? Yes, that would include the standard road surface conditions, which were previously diagnosed via preset values programmed into a data map, but now a continuous stream of information can more accurate decipher real-time

The torquey Impreza engine is quite impressive best when hooked up to its auto-box, nipping off the line with virtually no hesitation and ever willing to quickly downshift when called upon for passing purposes. (Photo: Trevor Hofmann, Canadian Auto Press)

situations and respond accordingly via an on-board LAN (Local Area Network). The system measures engine torque, approximate steering angle, and speed differences between the front and rear axles, to accurately respond to the minutest changes in driving conditions to optimize traction and overall handling. That's a pretty sophisticated four-speed, no?

Not only is the shifter responsive, but due to the transmission upgrades along with the Impreza 2.5i's highly polished four-wheel fully independent suspension system, limited slip rear differential (LSD), engine-speed-sensitive power-assisted rack-and-pinion steering system, and new 16- by 6.5-inch five-spoke alloy wheels on 205/55 R16 89V Bridgestone Potenza RE92 M+S all-season tires, the entire car reacts deftly to driver input over any road surface.