PACCAR MX Engine Earns California Certification

June 1, 2010, Bellevue, Washington PACCAR today announced that the California Air Resources Board (CARB) has certified the PACCAR MX 12.9-liter diesel engine to the 2010 emission standards.  The CARB certification, in conjunction with the EPA 2010 emissions certification previously received, allows the PACCAR MX engine to be installed in Kenworth and Peterbilt vehicles sold in all 50 states, effective immediately.

"We are pleased that Kenworth and Peterbilt customers will be able to benefit from the PACCAR MX engines industry-leading reliability and fuel economy," said Jim Cardillo, PACCAR president.

"The PACCAR MX engine is designed to deliver outstanding performance in a wide range of applications," said Craig Brewster, PACCAR vice president.  "The PACCAR MX engine achieves the EPA and California certification and meets the stringent emission standards of 0.2 grams per brake horsepower hour of NOx and 0.01 grams per brake horsepower hour of particulate matter.  This is accomplished through an effective combination of selective catalytic reduction (SCR), controlled exhaust gas recirculation (EGR) and a diesel particulate filter."

PACCAR is a global technology leader in the design, manufacture and customer support of high-quality light-, medium-, and heavy-duty trucks under the Kenworth, Peterbilt, and DAF nameplates.  PACCAR also designs and manufactures advanced diesel engines and provides financial services and information technology and distributes truck parts related to its principal business.  PACCAR shares are traded on the NASDAQ Global Select Market, symbol PCAR.  Its homepage is www.paccar.com.