The Mazda 3 will be sold with an emissions-saving stop-start system later this year.
The new car, which goes on sale this spring, is already cleaner by up to 13g/km of CO2 compared with the old model. However, the stop-start system will reduce this further.
Mazda has also ruled out seeking emissions savings by following VW's lead and building smaller, turbo- and supercharged engines.
Instead, it says that it will seek reductions through improvements to its transmission technology. Although Mazda has not specified exactly how it will achieve this, speculation suggests the company is developing a semi-automatic gearbox, similar to VW's DSG system.
Mazda 3 buyers will be able to choose from reworked 104bhp 1.6-litre and 148bhp 2.0-litre petrol engines, a revised 108bhp 1.6-litre diesel and two versions of Mazda's new 2.2-litre diesel: one delivering 148bhp and the other 183bhp.
Early testing by What Car? suggests that the new car is more refined than its predecessor, and that the interior plastics have improved slightly.