The improvement comes from revised gear ratios designed to give improved low end performance and driveability in city traffic. The new model goes on sale in the middle of next month and Saab says it is expected to become the best-selling engine in the 9-3 line-up.
Top speed of the new engine is 130mph in manual form and 127mph in automatic guise with the former offering 30mpg and the latter offering 26.6mpg. The new unit offers 154bhp and, while similar to the 150bhp version in the larger Saab 9-5, it offers more torque than the outgoing 2.3-litre unit.
The new engine is available in three-door, five-door and convertible 9-3 models costing £19,645 on the road as a three-door and £20,145 as a five-door in S trim, £21,395 and £21,895 respectively in SE trim and £27,195 as an SE convertible.