Saab is introducing low-emission versions of its 9-3 model.
Two engines are available: a 148bhp 1.9-litre diesel that emits 137g/km of CO2 and averages 54.3mpg, and a 177bhp 1.9-litre diesel that has CO2 emissions of 139g/km and averages 53.3mpg.
The figures represent average emissions savings of 7%, which have been achieved by revising gear ratios, remapping the engines' software and fitting low-rolling-resistance tyres.
Saab says 0-60mph times are unchanged, and fifth gear 50-80mph acceleration times are increased by less than one second.
Saab is marketing the lower-emission cars under its Ecopower banner.