PSA Peugeot-Citroen has developed a new diesel particulate filter with a service life of more than 150,000 miles, meaning the systemwill effectively be maintenance-free.

The breakthrough has come with the use of a new filter medium architecture called Octo-square – referring to the shape of the filter's intake channels – and Eolys, an improved fuel additive.

The first generation of particulate filters for diesel engines required servicing every 50,000 miles, but with the Eolys additive introduced last November their life was extended to more than 75,000 miles.

The latest filter and uprated version of Eolys will be offered with new-build Peugeot 406 and 806 models and with Citroen C5 and C8. Eleven PSA diesel cars and CDVs will have the system within two years, becoming standard fit with common rail units.