Diesel Cars Dirtier Than Heavy Duty Diesel Trucks?

[SubLGT]

http://www.greencarcongress.com/2017/01/20170105-icct.html

Quote:
In Europe, the average amount of NOx present in exhaust emissions from modern diesel passenger cars under real-world conditions is more than double the levels from modern trucks and buses, according to a new briefing paper released by the independent research organization International Council on Clean Transportation (ICCT).

The ICCT paper shows data for 24 Euro VI buses and trucks, some tested on a chassis dynamometer by the Technical Research Centre of Finland (VTT), and others tested on-road using portable emissions testing equipment by the German type-approval agency KBA. On average, NOx emissions of the heavy-duty vehicles tested were approximately 210 mg/km. Currently, NOx emissions of Euro 6 diesel passenger cars under real-world driving conditions are approximately 500 mg/km, as determined by testing carried out by KBA and other European type-approval agencies. In addition, the average conformity factor—the ratio of the test result to the regulatory limit—for the heavy-duty engines was less than 1, meaning that on-road emissions stayed below the Euro VI engine type-approval test limits.

The differences are attributable in large part to differences in how light-duty and heavy-duty vehicle emissions are regulated……...

 

[09_GXP]

The key is the last sentence of the quote you provided. I'm not sure about Europe but in the US the emissions testing is vastly different for passenger vehicles vs heavy duty vehicles such as semi-trucks. The key difference is that for passenger vehicles emissions are certified on a chassis dyno, "chassis cert," running a specified route and using calculated vehicle data such as aero loading. For heavy duty vehicles the engines are certified running in a test cell away from a vehicle, "dyno cert."

The standards in Europe are also different than the US standards. For diesel vehicles you are allowed more NOx in the US and more Carbon in Europe. This is one reason you can't directly port European diesel engines to the US.

 

[JHZR2]

How about per passenger or per ton mile?)

 

[Fsharp]

They're probably burning hotter and leaner than heavy duty diesels in order to reduce other types of emissions, CO hydrocarbons and soot.

 

[B320i]

The article makes a HUGE mistake.

There is a substantial difference between Euro VI and Euro6. One is for heavy vehicles, the other for passenger vehicles.

The EuroIV and V days saw a big push towards "Lean burn" technology in CNG-powered vehicles, which is why turbo-chargers became the norm from that point. Of course, this sent NOx through the roof, so now they've changed their game to stoichiometric to comply with EuroVI and found other ways of reducing NOx.