Germany on Friday cleared away legal hurdles for automakers to upgrade exhaust emissions filtering systems on older diesel vehicles as a way to prevent vehicle bans, but failed to quell doubts among producers and suppliers over the effectiveness of retrofits.
Automakers have been forced to think about upgrading exhaust treatment systems on older cars after German towns started prohibiting heavily polluting diesel vehicles to curb pollution from fine particulate matter and toxic nitrogen oxides.
The battle over refits is the recent fallout from an emissions cheating scandal caused by Volkswagen in 2015 after it admitted systematically evading illegal pollution levels from regulators.
An environmental and regulatory backlash ensued and lawmakers and the vehicle industry are now at odds regarding the clean up of dirty air in inner cities.
Automakers want customers to purchase new cars with cleaner engines, while environmentalists and consumer groups debate that retrofitting older vehicles may be more cost-effective.
The transport ministry on Friday released a 30-page document setting out guidelines for getting regulatory approval to set up upgraded exhaust filtering systems on older cars.