Mack Trucks announced its new Mack MP13 diesel engine for EPA 2027 emissions regulations and outlined the 2027 powertrain changes for its lineup of Class 6-8 trucks during the Advanced Clean Transportation Expo in Las Vegas.

The MP13 is the most powerful and efficient engine Mack has ever produced. It delivers up to 540 horsepower and 1,950 lb.-ft. of torque while providing up to 3% improved fuel efficiency compared with previous MP13 engines.

In addition, it delivers stronger stopping power, with up to 630 braking horsepower — more than 20% improvement over its prior iteration.

The updated Mack mDrive automated manual transmission complements the engine with faster engine-to-transmission communication for quicker, smoother shifts.

The MP13 meets EPA 2027 emissions standards through engine enhancements that deliver a more complete combustion and lower engine-out CO₂, soot and particulate matter.

It attains a nearly 75% reduction in nitrogen oxides (NOx) over the previous engine.

The MP13 also features an optimized torque curve that delivers peak torque as low as 900 RPM for improved drivability and downspeeding, a more efficient turbocharger, and advanced predictive software that smooths engine response to driver demands.

How Mack is Meeting Emissions Limits

The new MP13 is essentially the same platform as Volvo’s new D13 EPA 2027 engine, but with horsepower and power curves designed for Mack customers, said Govi Kannan, SVP global product owner, during a press conference at ACT Expo.

It features the new compact graphite iron block and an added heater system for the aftertreatment.

The graphite iron block is lighter weight than the previous block, offsetting some of the additional weight from changes to the aftertreatment.

The MP13 is also compatible with renewable diesel (R100) and biodiesel blends up to B20 — up from B10 on the previous MP13 — giving fleets added flexibility to incorporate lower-carbon fuels where available.

The EPA 2027 MP13 will be available for order beginning in August 2026, with production timed to model year 2028 vehicles.

Mack, like other engine makers, is still waiting on the promised revisions to the EPA 2027 emissions requirements. Although the EPA previously announced that the emissions limits would be unchanged, it is widely expected to modify or drop requirements for warranty and useful life that were expected to add significantly to the price of the new engines.

EPA at one time had projected that rulemaking would happen in May, but Kannon told reporters that it’s expecting it will be another three months.

What Engines Are Available in Mack Trucks for 2027?

The EPA 2027 MP13 will be available across Mack's highway and vocational lineup.

In the Mack Pioneer and all-new Mack Anthem, the MP13 delivers fuel efficiency for long-haul routes.

In the all-new Mack Granite, it brings up to 3% improved fuel efficiency for demanding vocational operations compared with the previous engine.

In the all-new Mack Keystone, the MP13 helps deliver up to 6% improved fuel efficiency compared with the Pinnacle, reducing operating costs without sacrificing the terrain versatility for which the Keystone is built.

Also for 2027, Mack is sunsetting its 11-liter engines (the MP7 and MP8), which will be replaced with new X10 engines being developed with Cummins. A miniature mockup of the new X10 was on display at the Mack booth.

• In the Mack Granite, customers will have a choice of the new MP13 or the new X10.
• Mack’s low-cabover TerraPro will move from the current MP7 to the X10.
• The Mack MD will continue with the B6.7.