What are the EPA 2007 On-Road Emission Standards?

The EPA 2007 on-road emission standards apply to model year 2007 and later heavy duty diesel highway engines. Off-highway vehicles are regulated by a separate EPA legislation. The on-road standards include two components: diesel fuel regulation and stringent emission standards. Beginning September 2006, the diesel fuel regulation limits the sulfur content in on-highway diesel fuel to 15 ppm down from the previous 500 ppm.

For model year 2007 trucks, the EPA emissions standards are:

• Particulate matter (pm): 0.01 g/bhp-hr;
• Nitrogen oxides (NOx): 0.20 g/bhp-hr;
• Non-methane hydrocarbons (NMHC): 0.14 g/bhp-hr;
• Formaldehyde: 0.016 g/bhp-hr;
• Carbon monoxide: 15.5 g/bhp-hr.

The particulate emissions standard will take full effect in the 2007 heavy duty engine model year. The NOx and NMHC standards will be phased in for diesel engines between 2007 and 2010. The phase-in will be on a percent of sales basis: 50% from 2007 to 2009 and 100% for 2010.