Environmental Protection Agency regulations in 2010 will require a reduction in Oxides of Nitrogen (NOx) emitted from diesel engines to "near zero" levels, as noted by the green box in the chart at right. PACCAR will utilize Selective Catalytic Reduction (SCR), an exhaust after treatment technology, to achieve the required NOx levels, providing customers a solution that protects the environment, and increases engine fuel economy and reliability. The alternative approach to meeting 2010 emissions requirements is to increase the levels of Exhaust Gas Recirculation (EGR) in the engine combustion process.
PACCAR has carefully evaluated each technology and concluded that SCR provides a number of distinct advantages over in-cylinder EGR designs including:

• Fuel Economy - SCR offers up to 5% improvement of '07 engine designs. EGR-only engines are estimated to result in a 5-9% loss versus today's engines.
  
• Reliability - Higher EGR flows result in 20-30% higher heat rejection and excessive acidic condensation that corrodes internal engine systems.
  
• Power Loss - EGR engine users can expect a deterioration of 50-100 horsepower for the same displacement and reduced throttle response.

For more information on this, Please contact our office.