In-Use Performance and Durability of Particle Filters on Heavy-Duty Diesel Trucks

Publication Type

Journal Article

Date Published



Diesel particle filters (DPFs) are standard equipment on heavy-duty diesel trucks with 2007 and newer engines in the U.S. This study evaluates the performance and durability of these filters. Black carbon (BC) emission rates from several thousand heavy-duty trucks were measured at the Port of Oakland and Caldecott Tunnel over multiple years as California regulations accelerated the adoption of DPFs. As DPF use increased, fleet-average BC emissions decreased, and emission factor distributions became more skewed. Relative to 2004−2006 engines without filters, DPFs reduced BC emission rates by 65−70% for 2007−2009 engines and by >90% for 2010+ engines. Average BC emission rates for 2007−2009 engines increased by 50− 67% in 2015 relative to measurements made 1−2 years earlier. Some trucks in this cohort have become high-emitters, indicating that some DPFs are no longer working well. At the Port, where DPFs were universal in 2015, high-emitting 2007−2009 engines (defined here as emitting >1 g BC kg−1) comprised 7% of the fleet but were responsible for 65% of the total BC emitted. These observations raise concerns about DPF durability and the prospects for fully mitigating adverse effects of diesel particulate matter on human health and the environment.


Environmental Science Technology



Year of Publication