Mack Trucks Adds 23,000-Pound Rear Axle and 325 Horsepower Engine Rating for Mack® MD Series
GREENSBORO, NC (March 20, 2025) – In an effort to give Mack Trucks’ vocational customers improved durability and broader options for their applications, Mack announced today it now offers a 23,000-pound rear axle and Cummins B6.7 engine with up to 325 horsepower on its Mack® MD Series models.
Designed for a Gross Axle Weight Rating (GAWR) of up to 23,000 pounds, the heavier axle and suspension offer increased capability for hauling loads requiring the most durable of trucks. The Mack MD with the 23,000-pound rear axle specifically benefits refuse packers with 11-yard up to 20-yard rear loaders, as well as those Mack MD models being utilized as water trucks holding 2,000 to 2,500 gallons of water.
When paired with the 325 horsepower engine rating and the Allison 3000RDS transmission, the Mack MD is now capable of increased towing capacity if the customer has a trailer.
“The 23,000-pound rear axle expands the applications in the vocational market – with refuse and construction reaping the most benefits,” said Tim Wrinkle, Mack vice president of vocational and medium duty. “The 325 horsepower also offers carriers traversing longer routes or in a hilly or mountainous region a more durable and reliable powertrain. The rear axles on those truck models equipped with a dump body, hook lift or roll-offs take some abuse during the truck’s lifespan. The heavier axle rating has better durability, and the larger horsepower engine will provide enhanced performance.”
The Mack MD6, a Class 6 model, has a Gross Vehicle Weight Rating (GVWR) of 25,995 pounds, and the MD7, a Class 7 model, has a GVWR of 33,000 pounds. Both models are exempt from the 12 percent Federal Excise Tax (FET).
The Mack MD Series models meet the needs of trucking applications requiring dry van/refrigerated, stake/flatbed, dump and tank truck vocations. The MD6 model does not require a Commercial Driver’s License (CDL) to operate for non-hazardous payloads.
The Mack MD Series is an all-new model range built specifically for medium-duty applications. Available in 4x2 configurations, the MD6 and MD7 models feature a sharp wheel cut for enhanced maneuverability for tough urban settings. The MD Series cab was updated in January to a larger cab with bumper-to-back-of-cab (BBC) measurement of 107 inches providing industry-leading comfort. Mack matched the bold look and styling of the Mack Anthem®, Mack’s highway model, as a basis for the grille and hood design found on the MD Series.
The interior boasts premium satin aluminum trim, improved seating with lumbar support and enhanced LED lighting. New steering wheel controls for cruise control, telephone and audio functions have been added, increasing driver convenience and safety. All of these have been popular with Mack’s Class 8 customers.
The trucks now come standard with several enhanced safety features including new ABS (Anti-Lock Braking System) with ATC (Automatic Traction Control), radio mute in reverse and a park brake alarm.
Pre-wired body builder connections relocated air dryer and updated wheelbases to industry-standard Cab to Axle (CA) dimensions make the updated MD Series easier to install an even wider array of body installations than previously.
Customers interested in the Mack MD Series can visit their local Mack dealer or www.macktrucks.com.
CAPTION: In an effort to give Mack Trucks’ vocational customers improved durability and broader options for their applications, Mack announced today it now offers a 23,000-pound rear axle and Cummin B6.7 engine with up to 325 horsepower on its Mack® MD Series models.
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