Typical Saab turbo power
On the road, both 1.9TiD engines have a distinctly sporty character, further narrowing any perceptible difference between diesel and petrol engine performance levels – except in the frequency of visits to the filling station.
Saab turbo engines have always been characterised by an extremely strong and wide spread of torque, giving the kind of low and mid-range power that is needed in everyday real-world driving. The 1.9TiD engine delivers just this kind of performance, demonstrated by the fact that 90% of maximum torque, an impressive 315 Nm for the 150 bhp engine and 280 Nm for the 120 bhp version, is generated between 1750 and 3250 rpm.
Furthermore, the driving experience is enriched by a smoothness and refinement, together with a progressive torque build-up, that belies the presence of compression ignition. Engineers have helped to achieve this by calibrating the movement of the electronic throttle to deliver a response similar to Saab's petrol turbo engines. The process is optimised by a low-inertia, intercooled Garrett turbocharger, operating at 1.35 bar boost, which includes variable vane geometry (VNT) where the pitch of turbine blades is electronically adjusted for quick pick-up at low engine speeds.
Low levels of NVH (noise, vibration and harshness) inside the car are due to the engine's advanced combustion technology as much as its careful chassis installation. This includes the adoption of an electro/hydraulic power steering system, for improved fuel consumption, and additional tuning of the front suspension and wheel angles.
The high level of driving satisfaction is reflected in the standard fitment of a close-ratio, six gear manual gearbox that encourages driver involvement and complements the 9-3's sporty handling characteristics.
The optional six-speed Aisin AW automatic transmission for the 150 bhp engine is a first for Saab and unique in this sector of the market.
It is a smooth and adaptive unit, responsive to changes in engine load, road gradient or altitude, and quickly finds the ‘right’ gear without any irritating hunting. It features lock-up in all forward ratios, except first. The driver can also switch to manual control by using a sequential floor shift or optional steering wheel mounted paddle shift buttons.