The millionth Euro 6 BlueHDi diesel engine rolled off the assembly line at Tremery, in the Moselle region of France this week.

Two different sizes are manufactured at Tremery: 1.6 (100hp and 120hp) and 2.0 litre (150hp and 180hp). BlueHDi technology, which was gradually rolled out across the PSA Group's vehicles from September 2013, ahead of the introduction of the Euro 6 standard in September 2014, is now used on all Peugeot, Citroen and DS brand Euro 6-compliant diesel models.

BlueHDi technology continuously limits diesel engine pollutant emissions using three emissions control mechanisms fitted in the exhaust line: an oxidation catalyst, an additive-technology particulate filter to eliminate particulates in mass and number, and selective catalytic reduction (SCR) technology, which is positioned upstream of the particulate filter to significantly reduce the nitrogen oxides (NOx) released by the engine. BlueHDi technology is the subject of around 100 patents filed by PSA Group.

Tremery currently manufactures 7,000 diesel engines a day, of which 5,000 are 1.6 litre engines (815,000 units manufactured since its launch in 2014) and 2,000 are two litre engines (185,000 units manufactured since September 2013).

PSA powertrain and chassis engineering chief Christian Chapelle said: "After pioneering the use of the particulate filter in 2000 and being the first car-maker to use SCR technology on all its vehicles, this milestone of 1m BlueHDi engines – the most effective pollutant emissions reduction solution in the market – confirms PSA Group's commitment to offering its customers sustainable and clean mobility solutions."