Utter nonsense!...The pollutant comes almost entirely from diesel vehicles....
http://www.epa.gov/air/nitrogenoxides/basic.htmlThe Clean Air Act requires EPA to set national ambient air quality standards for “criteria pollutants.” Currently, nitrogen oxides and five other major pollutants are listed as criteria pollutants. The others are ozone, lead, carbon monoxide, sulfur oxides, and particulate matter. The law also requires EPA to periodically review the standards and revise them if appropriate to ensure that they provide the requisite amount of health and environmental protection and to update those standards as necessary.
All areas presently meet the current (1971) NO2 NAAQS, with annual NO2 concentrations measured at area-wide monitors well below the level of the standard (53 ppb). Annual average ambient NO2 concentrations, as measured at area-wide monitors, have decreased by more than 40% since 1980. Currently, the annual average NO2 concentrations range from approximately 10-20 ppb.
EPA expects NO2 concentrations will continue to decrease in the future as a result of a number of mobile source regulations that are taking effect. Tier 2 standards for light-duty vehicles began phasing in during 2004, and new NOx standards for heavy-duty engines are phasing in between 2007 and 2010 model years. Current air quality monitoring data reflects only a few years of vehicles entering the fleet that meet these strict NOx standards.
That appears to be fundamentally untrue......Diesels produce far more NOx than petrol vehicles...
I should have been more clear - petrol engine-out (no cat) NOx is about twice as high as diesel engine-out NOx.I am not an Automotive engineer, but your source seems to me to say that with a cat, the diesel spews 42/4 as much NOX as the gasser. (over ten times as much)
even so, this is fresh cats, no statment in the chart of drive cycle, useage, and other factors that the previous articles discussed, which indicate that cars in use exceed the expected amounts.
http://naei.defra.gov.uk/overview/pollutants?pollutant_id=6...Road Transport is the largest source of NOx in the UK, with industrial combustion and power generation also accounting for a large fraction of the emission total. Almost a third of the UK NOx emissions arise from road transport, most of which comes from diesel vehicles....