New research from North Carolina State University found that federal requirements governing diesel engines of MY 2010 tractor trailer trucks have resulted in major cuts in real world emissions of particulate matter (PM) and nitrogen oxides (NOx).
Dr. Chris Frey, professor of civil, construction and environmental engineering at NC State and Ph.D. student Gurdas Sandhu used a portable emissions measurement system to sample exhaust from diesel trucks while the trucks were in use on roads and highways.
Frey and Sandhu found that a truck in compliance with the older 1999 standards emitted 110 grams of NOx per gallon of fuel used, and 0.22 grams of PM per gallon of fuel used. A 2010 truck emitted 2 grams of NOx per gallon of fuel—a decrease of 98%. The PM emissions were 95% lower.
The NOx reductions stem from the implementation of exhaust gas recirculation and selective catalytic reduction technologies. The PM reductions are the result of installing diesel particulate filters into the tail pipes of diesel trucks.
The paper, “Real-World Measurement and Evaluation of Heavy Duty Truck Duty Cycles, Fuels, and Emission Control Technologies,” is forthcoming from Transportation Research Record, the journal of the Transportation Research Board (TRB). Sandhu is lead author of the paper. The research was supported by the North Carolina Department of Transportation and the National Science Foundation.