Emissions Management


SCR technology has been successfully used for many years in some of the harshest climates and industries including trucking, marine and stationary power applications. Over 500,000 vehicles are successfully performing with SCR technology; including over 125,000 PACCAR Engines. SCR provides a reliable, economical and effective technology to meet the EPA emission requirements. PACCAR engines utilize Selective Catalytic Reduction in conjunction with Exhaust Gas Recirculation to meet EPA emission standards.

Emissions and Environment

undefinedEnvironmental regulations and concern about clean air impact all of us. PACCAR engines achieve near-zero emissions of Particulate Matter (soot) and nitrogen oxides (NOx). PM is removed from the exhaust by use of an effective Diesel Particulate Filter (DPF). NOx emission control is managed through Selective Catalytic Reduction (SCR) technology. PACCAR uses Copper Zeolite wash coating in the SCR catalyst, the most effective, reliable, and economical method for reducing NOx to allowable levels.

How the Emission Control Aftertreatment System Works


1. Reduces Engine Soot
Diesel Particulate Filter: Reduces 85-95% of engine soot and particulate matter. The DPF's also reduce emission of hydrocarbons and carbon monoxide. A functioning filter on a diesel powered vehicle will emit no visible smoke from its exhaust pipe.
2. Uses Non-Toxic Solutions
DEF Doser: The DEF doser injects small amounts of DEF into the exhaust stream after it exits the DPF  In the SCR catalyst the DEF reacts with the NOx found in the exhaust.
3. Reduces NOx emissions
SCR Catalyst: Selective Catalytic Reduction is an exhaust after-treatment technology that uses a reductant (DEF) to convert NOx to harmless nitrogen and water vapor.
Benefits of SCR

3-5% net fuel economy improvementBecause the pollutants are reduced to near-zero levels within the exhaust stream, an engine with SCR after treatment will operate cooler, cleaner and more efficiently than engines with higher EGR levels. PACCAR engines with SCR technology will provide up to 5% fuel economy improvement compared to a non-SCR engine.

Simple Diesel Exhaust Fluid (DEF)

simple diesel exhaust fluidDEF is a harmless, safe-to-handle solution of purified water (67%) and Urea (33%) that is required on commercial trucks and buses equipped with SCR emissions control technology. PACCAR engines utilize SCR because it is the most effective and efficient method for reducing NOx emissions to allowable levels. DEF is used in a low volume, approximately 2-3 gallons for every 100 gallons of diesel fuel, and can be stored, dispensed and handled in bulk and smaller quantities. DEF is readily available from PACCAR dealers as well as many truck stops and travel centers.

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