Before a PACCAR MX engine is put to work in a customer truck, the design gets run through a gauntlet of countless hours of testing to ensure quality, performance, and best-in-class service life.

Designed for one million miles (more to come on that point), the MX-13, up to 510 hp, or the smaller and lighter MX-11, up to 430 hp, is spec’d in the majority of PacLease Class 8 trucks in a full-service lease.

PACCAR’s Technical Center, nestled in Mount Vernon, Washington, about 70 miles north of Seattle, is a proving ground to end all proving grounds. Highly restricted and drone protected, this state-of-the-art facility conducts research and testing for all PACCAR divisions.

At the Tech Center, 400 driven employees, including structural and electrical engineers, materials scientists and powertrain experts pave the way for innovative technology development. The facility features a 1.6-mile banked high-speed oval track and a research and test facility on 375 acres near Padilla Bay.

PACCAR MX engines are designed with an industry-leading B10 life. B10 life is a big deal – it means 90 percent of the engines will reach one million miles without needing a major overhaul. That’s a big competitive advantage over other engines on the market.

The testing deep in the hills of Washington State is vital – it helps validate that these engines will meet the test of time for their first owner, as well as their second, and so on.

As new enhancements are designed for the engine, they undergo vigorous tests by world-class experts who have made testing a career at the Tech Center. They develop, test, and validate engines, powertrains, and vehicles to ensure all are best in class.

In addition, by running these tests, engineers are able to recognize potential changes they need to make, so that the engines can handle some of the harshest conditions in the world, like Death Valley, Canada’s Northwest Territories, and passes like Baker Grade in California.

After simulating these conditions at the Tech Center, test drivers take Kenworth trucks on the road to confirm that the vehicles perform under real-world conditions.

While PACCAR puts together a great engine, it also tears them apart. There’s always learning and validation that happens when Tech Center engineers take apart an engine with a million-plus miles. Being this

The Tech Center’s reputation is highly regarded, so too, is the PACCAR engine facility – a 450,000-square-foot engine and technology plant in Columbus, Mississippi. The plant was named the 2017 Quality Magazine Plant of the Year.

The PACCAR MX engine is known as a quiet, lightweight, and smooth operating engine that provides durability, fuel economy, and a first-rate power curve. MX power is the recipe for success for fleets looking for high performance.


The PACCAR MX Engine boasts a B10 design life of one million miles in linehaul applications. This means 90 percent of PACCAR MX Engines will log up to one million miles without a major overhaul, almost double the life of comparable engines.

The PACCAR MX Engine’s B10 design life stands as the pinnacle of our promise to you – a lifetime of unparalleled durability.