The Aero is distinguishable from the standard 9-3 by its front and rear spoilers, side skirts, rear bumper extension and 16-inch alloy wheels Its 2.0-litre full-pressure turbo engine generates 151kW at 5500rpm. The manual version has a peak torque figure of 280Nm from 2200rpm to 4600rpm while the auto generates 250Nm from 1900rpm to 5750rm Suspension settings have been uprated to provide sportier handling characteristics Transmission choices consist of a five-speed manual or optional four-speed automatic The 9-3 Aero is available in three-door, five-door and convertible body styles Saab front seats incorporate a mechanical Active Head Restraint system to reduce the risk of whiplash injuries Low-profile 205/50ZR16 tyres are standard on the Aero to enhance its grip and handling levels The body structure is designed to distribute the impact forces over as large an area as possible in an accident The front airbags are inflated by a soft charge, making them less aggressive to occupants seated well forward Two-stage head-thorax side airbags protect the occupants' rib cage and head in side impacts The audio system can be operated by controls mounted on the steering wheel Four-wheel disc brakes are complemented by an anti-lock braking system with electronic brake force distribution Boot capacity measures 494 litres with the rear seat upright