18 July 2007

The European Commission has launched a public consultation on the planned Euro VI emission regulation—the next tier of emission standards for heavy-duty truck and bus engines.

The Commission is soliciting comments from the stakeholders on four Euro VI emission limit scenarios (down from six scenarios in earlier consultations). The proposed PM and NOx limits, as well as the estimated associated CO2 increases, are summarized below. The consultation also specifies limits for other pollutants, limits for gas engines, and an ammonia limit of 10 ppm for SCR systems.

Euro VI Scenarios—Diesel Engines
PM, g/kWh0.010.020.0150.015
NOx, g/kWh0.
CO2 increase2-3%5-6%NeutralNeutral

Scenario A has limit values comparable to the US 2010 standards. Compliance would be achieved by using cooled exhaust gas recirculation and urea-SCR catalysts. However, this scenario would cause a 2-3% increase in CO2 emissions. A more relaxed Scenario D is also, “to a certain extent”, equivalent to the US standards, without the associated fuel economy penalty.

Scenario B is the most strict of all in terms of NOx emissions. It scenario requires a higher rates of cooled EGR than scenario A. In order to achieve such a high ratio of EGR, scenario B requires an improved cooling system. As a result, higher fuel consumption and thus higher CO2 emissions of around 5-6% are anticipated.

Scenario C is the least stringent in terms of NOx emissions; no negative impact is anticipated in terms of fuel consumption and CO2.

Stakeholders are requested to give their views on which of the scenarios is the most appropriate for implementation at the Euro VI stage. The Commission is specifically interested in whether stakeholders have a preference for stricter limits of pollutant emissions, even if this leads to higher CO2 emissions, or for lower CO2 emissions, even if this means less stringent pollutant emissions.

The Commission is also requesting input whether the public prefers that the Commission presents a proposal for Euro VI before the end of the year or that it prepares a proposal on the two next stages—Euro VI and Euro VII—even if this would mean delaying the proposal and the entry into force of the new legislation.

There is no indication as to the considered level of stringency for the Euro VII stage—for instance if the more strict Euro VI scenarios could become Euro VII standards, or else even more stringent limits should be adopted. There is also no indication if particle number emission limits, proposed for light-duty vehicles, will be considered for heavy-duty engines.

Comments are accepted by 5 September 2007.

Source: European Commission