Mack MD

The MD is the medium-duty truck line of Mack Trucks, rated in Class 6 and 7, the US gross vehicle weight classes explained in GVWR, GCWR and GAWR. Mack lists it as the diesel MD Series, whose page names the MD6 and the MD7 and describes the truck as “Mack’s heavy-duty toughness in a medium-duty truck”, and the battery-electric MD Electric. This page is built from Mack’s MD Series and MD Electric product pages, read on 4 November 2026, and from the article “Mack MD Grows With Customer Acceptance” in Mack’s magazine, March 2024.

Overview and production

Mack’s magazine dates the launch of the MD Series to 2020 and the launch of the MD Electric to March 2023, and says both are built at Roanoke Valley Operations (RVO), a plant in Virginia. According to Antonio Servidoni, Mack’s vice president of Roanoke Valley Operations, the MD Series put Class 6 and 7 trucks on the market built with “the same durability, reliability and comfort of Mack’s Class 8 vehicles”. The article also says the MD6 does not require a commercial driver’s license for non-hazardous loads.

In the same article Jonathan Randall, president of Mack Trucks North America, says the MD Electric is “in full production” and that customers are beginning to take delivery of it. The article reports a 72,000-square-foot addition to the plant, with ground to be broken that April and completion expected in Q4 of 2025, after which the facility would have 352,000 square feet, and a workforce of 420 in two shifts, expected to grow to around 500. No document opened reports whether the addition was completed, or names an earlier generation of the MD line.

Cab and interior

Both product pages describe a “New longer cab” with 4 inches more interior room and a 107-inch BBC (bumper to back of cab), and list four inches of additional legroom. The MD Electric page gives the cab as galvanised steel. Mack’s article of March 2024 gives the MD Electric a bumper-to-back-of-cab measurement of 103 inches, which differs from the 107 inches on its product page.

On the MD Series page the steering wheel has a flat bottom and carries cruise, phone and radio controls, on a tilt and telescopic column, and a dual-airbag cab suspension is standard. Under “Seating” the page describes a new premium driver’s seat with increased recline, adjustable lumbar support and a choice of vinyl or Mordura upholstery; its equipment lists give an air-suspension driver’s seat as standard and the premium seat and the Mordura cloth as options. Driver and passenger seat belts are adjustable, an overhead console provides storage, four LED dome lights replace two halogen bulbs, and the gauges are large and digital. The page’s other standard features are air conditioning, cruise control, an AM/FM radio with Bluetooth, console cup holders, 12-volt and USB outlets, bright-finish and lower convex mirrors, power steering, and power windows and locks. The MD Electric page lists the same console, dome lights, seat belts and steering column, and adds a two-person bench seat and an integrated air conditioner.

Behind the cab, the MD Series page lists a clear back-of-cab above the frame and clear side-frame space, with pre-wired body-builder connections to the Cummins engine and the Allison gearbox.

Engines

The MD Series page lists one diesel engine, the Cummins B6.7, in two series.

The page’s summary block gives 220–300 hp and 560–660 lb-ft; its lower torque figure differs from the 520 lb-ft in the engine table. Mack gives power in horsepower and torque in pound-feet. No document opened gives kilowatt or newton-metre figures, the individual ratings within each series, a cylinder count or an emission standard for the engine. The engine itself is described in Cummins B6.7 engine.

Transmissions

The page lists no manual or automated manual gearbox; these types are set out in truck gearbox types. Fuel Sense 2.0 MAX is listed as an optional Allison upgrade.

Axles, suspension and brakes

The MD Series page names Meritor for both the front axle and the drive axle and prints no axle ratings. A rear leaf-spring suspension is standard, and the page’s specifications name the leaf suspension Mack Multi Leaf; the optional air suspension is the Mack AL AirRide, which Mack describes as a dual-airbag design. Powder-coated disc wheels are standard.

Mack’s article of March 2024 says the MD Electric is available in 4x2 configurations with “a sharp wheel cut”. Wheel formulas are explained in axle configurations. No document opened gives the brake type, the wheel and tyre sizes, a wheel formula for the diesel MD Series or a wheel-cut angle.

Frame, wheelbases and weights

The MD Series page lists “120,000 PSI yield frame rails”, with a footnote: “Only available on MD7. MD6 features 110k PSI frame rails.” The MD Electric page lists the same 120,000 PSI rails without that footnote.

Both product pages give a GVW of 25,995–33,000 lbs. No document opened gives a GVW for the MD6 and the MD7 separately, a kerb weight, overall dimensions, or fuel or DEF tank capacities.

Safety and driver-assistance systems

The MD Series page lists anti-lock brakes with automatic traction control and adjustable seat belts as standard. A passenger peep window serves lane changes, backing up and right turns, and full-width grated steel steps serve entry and exit. Mack says the heated LED headlights increase forward visibility by up to 29% and side visibility by up to 50%; the page does not state the reference. Mack’s article of March 2024 mentions “a robust safety package” without listing its contents, and no document opened names collision-mitigation or other driver-assistance systems. Both product pages name a Geotab system for performance tracking.

Battery-electric MD Electric

The MD Electric page rates the truck in Class 6 and 7 and names an all-electric drivetrain with NMC battery packs.

The page gives the capacities as 150 and 240 kWh and the ranges and charging times by number of batteries, 2 or 3; it does not tie the capacities to the battery counts. No document opened gives a usable capacity, a distinction explained in installed vs usable battery capacity. A footnote on the range figure says it is based on Mack internal testing and that actual range, motor output and charge times may vary with battery condition, charger output and environmental factors.

Mack says the batteries are mounted “between the all steel frame”, and lists an all-steel front bumper and a flat back-of-cab that it describes as giving clean electrical connections for body installation. A copper bulldog marks a truck with Mack’s electric powertrain. No document opened gives the motor’s output in kilowatts, a kerb weight, a top speed or the position of the charge port.

Source notes

Mack’s MD Series page, read on 4 November 2026: Class 6 and 7, GVW 25,995-33,000 lbs; Cummins B6.7, 6.7 l, Efficiency Series 220-260 hp and 520-660 lb-ft, Performance Series 280-300 hp and 660 lb-ft; the page’s summary gives 220-300 hp and 560-660 lb-ft. Allison 2500 HS, 2500 RDS and 3000 RDS, all 6-speed automatic. Meritor front and drive axles; Mack Multi Leaf or Mack AL suspension. Frame rails of 120,000 PSI on the MD7 and 110k PSI on the MD6. 107 in BBC; wheelbases of 151, 175, 187, 205, 217, 235, 255 and 274 in. MD Electric page, read on the same day: 3-phase permanent magnet synchronous motor, 185 hp continuous and 260 hp peak, 960 lb-ft continuous and 1,850 lb-ft max; NMC batteries of 150 or 240 kWh installed capacity; maximum range 140 miles (2 batteries) or 230 miles (3 batteries); maximum payload 19,400 lbs; CCS1 charging, AC 19.2 kW and DC 80 kW; wheelbases of 205, 217, 235, 255 and 274 in. Mack’s magazine, March 2024: MD Series launched in 2020, MD Electric in March 2023, both built at Roanoke Valley Operations, Virginia; a BBC of 103 inches and 4x2 configurations for the MD Electric. No Mack document opened gives engine or motor output in kilowatts, torque in newton-metres, a kerb weight, overall dimensions or tank capacities.