The 2017 Subaru Impreza has made its motor show debut but an eagle-eyed Practical Motoring reader has caught it testing in Japan.

AN EAGLE-EYED Practical Motoring reader has spied the Subaru Impreza testing in Japan ahead of its launch later this year. Locally, the Impreza is expected to launch late in December and go on-sale in January.

While Subaru has released official images of the exterior and interior of the all-new Impreza, which is the first Subaru to benefit from the brand’s new global platform, the leaked Japanese brochure confirms the size increase of the new Impreza, sadly, we can’t read the Japanese on the other part of the brochure which details key new features of the vehicle.

Available in both sedan and hatchback form, the new Impreza will be bigger than the outgoing model: 4625mm long (up 45mm); 1775mm wide (up 35mm); 1455mm high (down 10mm) and the wheelbase will be increased to 2670mm (an increase of 25mm). While the hatchback runs the same wheelbase and width at 4460mm it’s shorter than the sedan, at 1480mm high it’s also taller than the sedan. The rear seats in the Impreza hatch fold down flat, although there is a slight lip.

Looking at the on-road pictures, the new Impreza is clearly an evolution of the current car and to my eyes it looks good.

Subaru’s global platform promises, according to the Japanese car maker, benchmark setting ride and handling, NVH and safety. “Optimized frame structure and stronger joints between parts” mean overall torsional rigidity is up by 70% over current models. This structure stiffness helps to distribute “the resonance and distortion throughout the body” helping to make it very quiet. And by mounting the rear stabiliser directly to the body, the new platform reduces body roll by 50% compared to present models.

Subaru has also announced Active Torque Vectoring will be fitted. In terms of the engine, around 80% of the parts on the FB 2.0-litre direct-injection Boxer engine (112kW) have been completely revamped, making it lighter, delivering more power and fuel efficiency. Although rumours suggested Subaru might include cylinder deactivation, there’s been no mention of that by the Japanese car maker.

As hoped, the CVT has been tweaked and borrows the full-auto stepped shifts from the WRX which will help to make this CVT the benchmark transmission of its ilk in this class, and that’s not damning it with faint praise. It features a seven-speed manual mode function.

Subaru Australia hasn’t said what specs we’ll see on the new Impreza when it arrives Down Under, but globally the thing will be offered with EyeSight, including Pre-Collision Braking Control, Adaptive Cruise Control, and Lane Keep Assist. Also offered will be High Beam Assist which is linked to the EyeSight stereo camera, automatically switching from high to low beam according to what is happening ahead of the vehicle. Steering Responsive Headlights move the beam right or left when turning, illuminating the direction of travel. Impreza employs the two headlight controls for the first time, dramatically improving night-time visibility and the recognition capabilities of EyeSight.