BERLIN, March 14 (Xinhua) -- German carmaker Volkswagen suggested that technical upgrades for its diesel vehicles would offer a feasible means of lowering excessive nitrogen oxide emissions in Germany, the newspaper Zeit reported Wednesday.
An internal analysis conducted by the Wolfsburg-based company in 2016 estimated that available "modular" exhaust systems could be fitted in 70 percent of diesel vehicles sold, including popular models such as the Volkswagen Passat and Golf, Audi A3s and Skoda Octavia.
By contrast, a "new development" would be required for the remaining 30 percent of diesel cars in order to lower their nitrogen oxide emissions.
The report raised questions over Volkswagen's official stance on technical upgrades. As recently as Tuesday, chief executive officer Mathias Mueller reiterated to press that, unlike cheaper software upgrades which his company was already committed to, such measures were "not sensible".
According to the internal document, Volkswagen had most of the necessary components in its own stock and could have begun upgrading vehicles in 2018.
Responding to the news on Wednesday, however, the automotive company said that the information cited by Zeit was part of an analysis which was "exclusively concerned with the mechanical scope" for technical upgrades and did not consider their economic feasibility.
Calls for driving bans have recently gained renewed momentum in Germany after a landmark ruling by the Federal Administrative Court in the ongoing "dieselgate" scandal empowered municipal governments to adopt such radical measures unilaterally.
Earlier, Berlin had admitted that at least 20 German cities would fail to comply with European Union (EU) urban air quality regulations by 2020.
According to the Federal Environmental Agency (UBA), technical upgrades of diesel vehicles are a costly but effective potential means of preventing the imposition of driving bans.