Features:
1.5-liter DOHC engine (15S) and 2.0-liter SOHC engine (20S)
The equal length/constant pulsation independent exhaust system substantially elevates exhaust efficiency through reduced interference between cylinders, which helps deliver optimal torque in various ranges of speed.
The Active Valve Control System (AVCS) hydraulically controls timing in the intake valves and helps to increase combustion efficiency and improve low-end torque on the 15S.
Various parts of engine employs friction-reducing technologies, including lowered load in the valve springs, mirror-surface machining, and molybdenum coating��on the valve lifters. Fuel economy and emission reduction are greatly improved on the 15S.
b) 2.0-liter turbo engine (S-GT)
The Dual Active Valve Control System (Dual AVCS) hydraulically controls timing in both the intake and exhaust valves, which helps increase combustion efficiency and improve low-end torque, and ensures linearly responsive acceleration to depressed pedal movement.
The equal length/constant pulsation independent exhaust system substantially elevates exhaust efficiency through reduced interference between cylinders, which helps deliver optimal torque in various ranges of speed.
A tumble generated valve (TGV) has been installed in the intake manifold, boosting combustion efficiency by controlling the intake flow. It improves efficiency particularly at the time of engine ignition.
Also adopted is a secondary air system that forces air into the exhaust port to burn out any gasoline remaining in it. The system helps eliminate harmful substances when the powertrain is still cool, and it promotes early activation of a catalytic converter.
A new compact turbine boasts quicker response. After optimization of the shape of its turbine housing, the turbo unit has been greatly improved to deliver ideal output from low speed to high speed ranges.
A liquid-filled engine mount has been applied to reduce noise levels and improve ride comfort. The weight of the engine mount bracket has been reduced by utilizing plastic material.
c) Transmissions/AWD
(All-Wheel Drive) system
Automatic transmissions have been modified for faster, more accurate, responsive shifts, while fuel economy is improved through reduced friction. AT models come with SPORTSHIFT* mode in which a driver can enjoy manually changing gears.
* SPORTSHIFT is the registered trademark of Prodrive. Ltd.
By choosing the AT Select lever and ECO Switch in the AT models, 3 modes of driving are available: Eco; Sport; and Manual.
The N Control System on AT models automatically shifts the transmission back to neutral from driving positions after the brake pedal is depressed for some time, as when waiting at a traffic light.
The Active Torque Split AWD system is mounted on AT models. MT models come with the center differential AWD system with viscous LSD (limited slip differential).
The lower center of gravity, enabled by the Boxer engine, has been enhanced by mounting the engine front 22 mm lower on the chassis, thereby further improving stability.
The strut-type front suspension is supported by newly designed front cross members. Employing box-shaped steel tubing, the new cross members further support the suspension, as well as improve crash worthiness.
Thanks to these high-strength cross members, subframe parts have been largely eliminated, making the front floor section much lighter and enabling better handling and improved maneuverability.
The newly designed double-wishbone rear suspension effectively absorbs shocks from road surfaces, ensuring high levels of ride comfort and agile handling as well as effectively lowering noise levels.
The brake system employs tie rods for the brake booster, ensuring steady braking and control.
The hill-start assist function maintains the braking function one second after the brake pedal is released in case of starting a car on a hilly road. (Available on the S-GT MT model with Vehicle Dynamics Control, VDC)
Streamlined body construction and the extensive use of high-tensile steel, including 590 MPalevel steel for major body frames, the new Impreza has achieved both high body rigidity and a weight reduction of 20 kg.
