Peterbilt Announces CARB Low NOx Compliant PACCAR MX-13 Engine Availability in Models 579, 567 and 589

Peterbilt Announces CARB Low NOx Compliant PACCAR MX-13 Engine Availability in Models 579, 567 and 589 - Hero image

Denton, TX, June 4, 2024 — Peterbilt is pleased to announce the availability of a new CARB low nitrogen oxide (NOx) compliant PACCAR MX-13 engine in the Models 579, 567 and 589. This engine meets the CARB Omnibus Regulation and features redesigns of internal hardware and the aftertreatment system to effectively reduce NOx emissions.

The larger volume aftertreatment system includes an innovative compact twin assembly featuring a 48-volt generator located in the flywheel housing, and an electrical heater located in the inlet to provide lower NOx output. The internal hardware now features a larger volume mixer, longer selective catalytic converter (SCR) and an improved and more durable NOx sensor design with increased longevity for improved uptime. These features allow Peterbilt customers to achieve increased engine efficiency and fuel economy while continuing to meet stringent CARB emissions regulation.

The CARB low NOx compliant PACCAR MX-13 engine combines the proven diesel powertrain with next-generation technology. It is available in two ratings with a flat torque curve providing performance across a wider range of RPMs for excellent drivability and fuel economy. This includes a high performance 510-horsepower rating with 1,850 lb.-ft. of torque and an efficiency focused rating of 455-horsepower and 1,650 lb.-ft. of torque between 900 and 1,325 RPM.

“PACCAR MX engines were engineered for reliability and fuel economy in a comfortable, quiet and powerful package. The new CARB low NOx PACCAR MX-13 engine offers the same great features with a reduced carbon footprint for our customers,” said Scott Newhouse, Peterbilt chief engineer.

Peterbilt Models 579, 567 and 589 with the CARB low NOx compliant PACCAR MX-13 engine are available for orders now. For more information visit your nearest Peterbilt dealer or


Peterbilt Motors Company is recognized as the “Class” of the industry. With a complete lineup of diesel, natural gas and electric vehicles, Peterbilt has earned a global reputation for superior engineering, quality and craftsmanship. Peterbilt is Driving Uptime Every Day through innovative aftermarket services and advanced technology solutions delivered through its 425+ dealer locations in North America. Visit for more information. Peterbilt is a PACCAR Company, traded publicly on the NASDAQ as PCAR.

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