Peterbilt Model 567 and 589 Deliver 8–10% Fuel Economy Gains

Peterbilt Trucks Deliver Measurable Efficiency and Payload Gains

On September 3, Peterbilt Motors Company announced measurable fuel economy and payload improvements for vocational fleets using the Peterbilt Model 567 and Model 589 equipped with the PACCAR MX-13 engine and PACCAR TX-18 Pro 18-speed automated transmission. The improvements are particularly relevant to demanding vocational operations where fuel consumption, vehicle weight, and payload capacity directly affect operating costs and productivity. The announcement highlights how the combination of a heavy-duty engine and advanced automated transmission can improve fleet efficiency while supporting the demanding requirements of vocational applications.

Patuxent Companies Reports 8–10% Fuel Economy Improvement

Patuxent Companies in Maryland is replacing aging trucks with Peterbilt Model 567 and Model 589 vehicles equipped with PACCAR TX-18 Pro 18-speed automated transmissions. The company reported a significant improvement in fuel economy during its transition to the newer trucks. “We're seeing roughly an 8% to 10% improvement in fuel economy,” said Sam Gardiner of Patuxent Companies. The reported improvement demonstrates the potential operating benefit of the updated powertrain configuration for vocational fleets that accumulate substantial mileage and operate under demanding load and route conditions.

Lower Transmission Weight Supports Higher Payload Capacity

In addition to improving fuel economy, the PACCAR TX-18 Pro provides a substantial weight advantage compared with the transmissions it replaces. According to Gardiner, the 18-speed automated transmission is more than 400 pounds lighter than the previous units. That reduction creates additional available weight capacity for trucks equipped with aluminum bodies, allowing operators to increase payload while remaining within applicable vehicle weight limits. For vocational fleets, where carrying capacity can directly influence productivity and revenue per trip, reducing component weight can provide an important operational advantage alongside the reported fuel economy improvement.

TX-18 Pro Designed for Rigorous Vocational Applications

The PACCAR TX-18 Pro 18-speed automated transmission was purpose-built for rigorous vocational applications that require both precise vehicle control and broad operating capability. Its ratio coverage includes additional low-end ratios and multiple reverse gears, giving drivers greater flexibility across demanding operating conditions. The transmission allows drivers to slow down when extra precision is required or increase speed when conditions permit, while maintaining a focus on fuel efficiency and payload. This combination of gearing flexibility and automated operation is intended to support vocational work where terrain, maneuverability, and load requirements can vary significantly during daily operations.

PACCAR and Eaton Cummins Partnership Enables the Transmission

The PACCAR TX-18 Pro 18-speed automated transmission is enabled by its partnership with Eaton Cummins. The transmission forms part of the broader powertrain configuration available for the Peterbilt Model 567 and Model 589 vocational trucks discussed in the announcement. Together with the PACCAR MX-13 engine, the transmission is designed to deliver the ratio coverage and operating characteristics required for demanding vocational use. The reported results from Patuxent Companies provide a real-world example of how the transmission's lower weight and gearing capabilities can contribute to fuel economy and payload improvements in fleet operations.

Frequently Asked Questions

What fuel economy improvement did Patuxent Companies report?
Patuxent Companies reported roughly an 8% to 10% improvement in fuel economy after adopting the newer vocational trucks equipped with the PACCAR TX-18 Pro transmission. Sam Gardiner of Patuxent Companies provided the estimate while discussing the company's replacement of aging trucks with Peterbilt Model 567 and Model 589 vehicles. The reported improvement reflects the company's operating experience with the updated powertrain configuration. Fuel economy performance can vary depending on vehicle specification, payload, operating conditions, routes, driving practices, and other fleet-specific factors.