Diesel technologies drastically cut emissions in real-world conditions

New research from North Carolina State University shows that technologies implemented as a result of federal requirements governing diesel engines of new tractor trailer trucks have resulted in major cuts in emissions of particulate matter (PM) and nitrogen oxides (NOx) -- pollutants that have significant human health and environmental impacts. 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. Dr. Chris Frey 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. The emission requirements apply to new trucks, meaning that trucks purchased in 2010 and trucks purchased in 1999 were subject to different emission requirements. Trucks in compliance with newer standards had far lower emissions. For example, a 2010 truck emitted 2 grams of NOx per gallon of fuel -- a decrease of 98 percent. The PM emissions were 95 percent lower.