The California Air Resources Board (CARB) low-nitrogen oxide (NOx)-compliant Paccar MX-13 engine is now available for Peterbilt models 579, 567, and 589. The engine includes updates to its internal hardware and aftertreatment system to help it meet the CARB Omnibus Regulation.
“Paccar MX engines were engineered for reliability and fuel economy in a comfortable, quiet and powerful package,” said Scott Newhouse, Peterbilt chief engineer. “The new CARB low NOx Paccar MX-13 engine offers the same great features with a reduced carbon footprint for our customers.”
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The engine’s updates include a larger volume aftertreatment system, which offers a compact twin assembly featuring a 48-volt generator in the flywheel housing, as well as an electrical heater in the inlet for lower NOx output. The internal hardware updates include a larger volume mixer, a longer selective catalytic converter (SCR), and a more durable NOx sensor design.
The engine overall is available in two ratings with a flat torque curve and is meant to perform across a wider range of rpms. The two ratings are 510-hp with 1,850 ft.-lb. of torque, and an efficiency-focused 455-hp rating with 1,650 ft.-lb. of torque between 900 and 1,325 rpm.
Peterbilt Models 579, 567, and 589 are available to order now.