17 November 2009

Volvo Trucks North America’s D11 and D13 engines and the Mack MP7 and MP8 engines have been certified by the US Environmental Protection Agency (EPA) and the California Air Resources Board (ARB) as meeting the upcoming 2010 diesel emission standards. Volvo/Mack is the first truck manufacturer to have its heavy-duty diesel engines certified for 2010.

The engines have been “fully certified to meet EPA’s stringent standards without the use of emissions credits”, said Volvo. The 2010 standards are 0.2 g/bhp-hr for NOx—approximately 80% reduction from typical certification levels in 2007 engines—and 0.01 g/bhp-hr for PM.

All heavy-duty diesel truck and bus engines produced after January 1, 2010 must meet the new standards. However, manufacturers who accumulated emission credits for engines that exceeded emission standards prior to 2010 can certify their engines at higher emission levels and use the credits to cover the difference. Therefore, manufacturers who have accumulated emission credits may be able to calibrate their engines to higher NOx levels to achieve a fuel economy benefit.

The Volvo and Mack engines utilize urea-SCR technology for NOx reduction. The fuel economy has been improved compared to 2007 engines, but no detailed figures were provided. In comparison to non-SCR engines, a further fuel economy benefit comes from diesel particulate filter (DPF) regeneration, as SCR engines can rely to a higher degree on passive regeneration due to the higher NOx concentrations in the DPF (positioned upstream of the SCR catalyst).

Source: Volvo, Mack