In 2021, PACCAR introduced several new upgrades to its PACCAR MX-11 10.8 L and PACCAR MX-13 12.9 L engines that are designed to optimize performance and efficiency for Class 8 trucks. Both engines feature redesigned internal components to enhance fuel economy—up to 2.4% in the PACCAR MX-13, and 3.4% in the PACCAR MX-11—depending on the application and specification. The PACCAR MX-11, designed for weight-sensitive applications, can now be spec’d with a higher hp rating up to 445 hp at 1,700 lb-ft of torque @ 900 RPM. The PACCAR MX-13 engine can be spec’d up to 510 hp at 1,850 lb-ft of torque @ 1,000 RPM.
In addition to fuel efficiency improvements, engineers added robustness to increase reliability and durability of the MX-11 and MX-13 engines. A fully encapsulated engine wiring harness protects against the elements, while connections were reduced between the engine and vehicle. Inside the engine, several structural enhancements were added to strengthen components, reduce wear, and optimize rigidity.
Other features include an enhanced multi-pulse fuel injection system, a smaller, more efficient turbocharger, and enhanced piston design intended to reduce frictional losses. For more about the EPA 2021 PACCAR MX-11 and MX-13 engines, visit paccarpowertrain.com.