What're The Differences Between Mack And Peterbilt Semi Trucks?

Among the handful of power players in the business of building Class 8 semi trucks, both Peterbilt and Mack garner a sizable chuck of the market. Data for 2023, reported by FleetOwner, shows that Peterbilt sells far more trucks, with 14.9% market share versus Mack's 6.8%. But beyond sales, what sets these brands apart?

Mack was founded in 1900 by a pair of brothers, Jack and Gus Mack. Since then, it has changed hands a few times, and it's been under the Volvo Group, now part of Zhejiang Geely Holding, since 2000. Mack Trucks are made primarily in Pennsylvania, Maryland, and Virginia, but Volvo Group is working on a new site in Mexico to expand its production. Mack is generally known for its heavy-duty construction, having forged this reputation during two world wars, and its durability, shown by its success in industrial applications.

Theodore A. Peterman launched Peterbilt much later, in 1939. In 1958, the Pacific Car & Foundry Company (Paccar) assumed ownership, which continues to this day. And Peterbilt isn't alone among semi truck brands Paccar owns. Paccar builds Class 8 trucks primarily in a large plant in Texas, but also has a facility in Quebec. According to a poll conducted by ET Transport, 42% of 2,000 truckers surveyed believe Peterbilt 579s are the best trucks available for interior comfort. 

In terms of price, you can find a 2026 Mack Pioneer sleeper model anywhere from just under $161,000 up to nearly $215,000. A 2026 Peterbilt 579 sleeper , meanwhile, can be found between $169,000 and almost $220,000, making them about even, depending on sleeper size, options, and trim.  

The Mack Pioneer and Peterbilt Model 579 are comparable Class 8 semi trucks that give an idea of what to expect from each brand. Mack offers five configurations of the Pioneer's cab, from the smallest day cab to the 76-inch-tall high-roof sleeper, along with three axle configurations. Peterbilt also offers five cab sizes, from 44 inches up to an 80-inch-high Ultra Loft, and a selection of axle designs. 

In terms of sleeper height, the largest Peterbilt 579 is taller inside than Mack's largest Pioneer by four inches. It can also be equipped with a flat-screen TV up to 32 inches. Which can make all the difference, considering it's a hard road for the American truck driver.

The Mack's behind-the-wheel experience includes a flat-bottom steering wheel, which affords more legroom during travel, and can make entering and exiting the truck easier — although the angled nature of the Pioneer's center dash may crowd a bit of that legroom. Peterbilt's 579 offers a much less aggressive angle to the dash, creating some space between the driver's right leg and the center console. And Peterbilt offers the larger digital instrument cluster, 15 inches, compared to Mack's 12-inch display. Peterbilt's system is also configurable, letting the driver prioritize certain gauges. 

Regarding safety technology, Mack includes active driver assist, automatic pedestrian detection, and lane keep assist. However, Peterbilt goes further, offering additional systems like highway departure braking and side object detection. But the Pioneer also offers an optional driver-assistance system called Mack Command Steer that uses an additional electric motor to help reduce the effort required to manipulate the steering wheel, such as when driving in windy conditions.

Under the hood of the Mack Pioneer is a proprietary 13-liter diesel engine, the MP13. Utilizing a variable-geometry turbocharger, this power plant can deliver up to 515 horsepower and a 1,950 pound-feet of torque. 

But it's not just raw output that's important for trucking, but arguably moreso efficiency, which is why semi trucks don't use V8s. Mack has centered its design around improving mileage. For instance, Mack engineers have added an oil pump that can automatically adjust flow rate, and incorporated a turbocharger that better manages thermals for better mpg performance. A test by Commercial Carrier Journal showed the Pioneer's predecessor nearing 10 mpg. Mack claims the MP13 gives up to a 3% increase in fuel economy, though official mpg figures aren't available.

The Peterbilt 579 offers several engine options such as the Paccar MX-13, a 12.9-liter. It pushes out a maximum of 510 horsepower and 1,850 lb-ft. The most robust option is the Cummins X15, a 15-liter capable of 605 horsepower and over 2,000 pound-feet of torque. 

Similarly to the Mack Pioneer, the Peterbilt 579 has gone beyond engine design in its quest to maximize fuel, and made several adjustments to the exterior to minimize drag. This is most evident in the 579 EPIQ package, which includes extras like skirts, wheel well covers, and more substantial fairings for aerodynamic flow. AAM Network, a trucking and logistics company, estimates its average fuel economy around 7.5 to 8 mpg, while drivers like Auquaholic on Reddit's r/Truckers have described their 579 getting as much as 9 mpg on flat runs hauling 80,000 pounds.