COMMENT: VW affair puts NOx in the CARB spotlight

It seems clear that, in the US, the ongoing Volkswagen passenger car cycle-beating imbroglio has focussed renewed attention on oxides of nitrogen (NOx) emission levels, just when manufacturers thought they could safely redirect their efforts towards cutting greenhouse gases (GHGs), principally CO2, and fuel saving.

During recent discussions among environmental groups, led as ever by the California Air Resources Board (CARB), on the proposed ‘Phase 2’ reduction in heavy-duty (truck and bus) GHG emissions