Re-designed MX-11 engine

PACCAR unveils upgraded engines

May 18, 2021
Re-designed MX-11, MX-13 engines built to deliver better MPGs, more horsepower and improved durability for operators

Along with the launch of Kenworth’s T680 Next Generation truck model, PACCAR also revealed re-designed MX-11 and MX-13 engines the company says deliver better performance and efficiency for its Class 8 vehicles.

Both 2021 engines feature re-designed internal components to enhance fuel economy—up to 2.4% in the PACCAR MX-13, and 3.4% in the PACCAR MX-11, PACCAR said—depending on the application and specification. The PACCAR MX-11 now can be spec’d with a higher horsepower rating of up to 445 hp at 1,700 pound-feet of torque at 900 RPM. The MX-13 can be spec’d up to 510 hp at 1,850 pound-feet of torque at 1,000 RPM.

These new engine developments make Kenworth trucks more productive. When paired with the 12-speed PACCAR TX-12 transmission, Kenworth predictive cruise control, and PACCAR DX-40 axles, the performance is enhanced further, the company maintained.

Helping drive fuel efficiency improvements is a number of refinements that come together to maximize performance. The engines feature optimized combustion with multi-pulse fuel injection. A smaller, more efficient turbocharger boosts power and improves responsiveness. And an enhanced piston design has added features to reduce frictional losses. PACCAR’s next generation aftertreatment system completes the system to further reduce particulates and NOx without sacrificing power or MPGs.

The engines were updated for added reliability. An enhanced, fully encapsulated engine 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 and optimize rigidity.

To make fuel filter changes more efficient, PACCAR now mounts primary and secondary fuel filters on the engine, instead of on the chassis. And a 12-volt fuel heater comes standard for improved cold weather performance.

Extended service intervals of up to 75,000 miles for both the oil and fuel filter combined with major components warranty, which is five years or 500,000 miles, results in best-in-class performance and service intervals, PACCAR said.

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