Peterbilt Motors Company is delivering measurable fuel economy and payload improvements for vocational fleets operating the Peterbilt Model 567 and Model 589 equipped with the Paccar MX-13 engine and the Paccar TX-18 Pro 18-speed automated transmission.

After decades of operating automatic transmissions in its dump truck fleet, Patuxent Companies is replacing aging trucks with the Peterbilt Model 567 and Model 589, specified with the Paccar TX-18 Pro 18-speed automated transmissions to improve fleet efficiency.

Founded in 1987, Patuxent Companies operates sand and gravel plants, recycling operations, and a large hauling fleet serving concrete producers, utility contractors, and site development projects across Maryland.

“We're seeing roughly an 8% to 10% improvement in fuel economy,” said Sam Gardiner of Patuxent Companies. “On average, that's about a half to one mile per gallon, depending on the driver. In this business, that adds up.”

Gardiner noted the 18-speed automated transmission is more than 400 pounds lighter than the units it replaces, weight savings that goes directly to payload capacity for their trucks equipped with aluminum bodies.

Purpose-built for the most rigorous vocational applications, the TX-18 Pro offers superior ratio coverage with additional low-end ratios and multiple reverse gears, enabling drivers to slow down for extra precision or speed up when conditions allow, all while maximizing fuel efficiency and payload.

“The combination of Peterbilt trucks and the Paccar TX-18 Pro transmission is delivering exactly what vocational customers need, greater efficiency, increased payload, and enhanced driver satisfaction,” said Erik Johnson, assistant general manager, sales and marketing for Peterbilt. “This partnership with Eaton Cummins reflects Peterbilt's commitment to driving uptime every day by providing solutions that help fleets stay productive and profitable.”

The Patuxent fleet rollout reflects broader industry trends, including changing driver demographics, rising operating costs, and increased emphasis on uptime. The Paccar TX-18 Pro transmission is engineered to meet the demands of vocational fleets that require durable, efficient, and driver-friendly configurations.