The Saab 9-3, Saab's near-luxury car, has no powertrain changes for what will probably be its final year. 2.0T models have a turbocharged 2.0-liter inline four. Known as the LK9, this 16-valve, DOHC engine is part of GM's Ecotec family. It is all aluminum, with cast-iron cylinder liners and twin balance shafts for greater smoothness. With a compression ratio of 9.5:1 and up to 12.3 pounds of boost from its intercooled turbocharger, the LK9 produces 210 horsepower and 221 lb-ft of torque.
Aero models have a 2.8-liter turbocharged V6. This 24-valve, DOHC engine, known as the LP9, is part of GM's High Feature family, manufactured in Australia. It is all aluminum, with a forged steel crankshaft and connecting rods, a variable intake manifold, and continuously variable timing for both the intake and exhaust valves. The version in the 9-3 has a compression ratio of 9.5:1 and an intercooled, twin-scroll turbocharger, with a separate inlet from each cylinder bank to reduce turbo lag. In 2008, Saab raised maximum boost pressure from 7.3 psi to 11.6 psi, increasing output to 280 horsepower and 295 lb-ft of torque.
The 2.0-liter engine suffers more turbo lag than newer designs like Volkswagen's 2.0 TSI engine. It is slightly weak at low speeds, and power comes on with a bang once the turbo spools up. The 2.8-liter V6 has less lag. The 2.8T performs well at all speeds, although it is no stronger than the normally aspirated V6s in rivals like the Acura TSX. Both 9-3 engines are smooth, but their persistent exhaust drone at cruising speeds annoys some reviewers.