Medium-duty trucks tackle a variety of tasks, operating in an environment with narrow roads, high congestion and access or parking restrictions, but with the right engine and transmission, fleets can have the confidence that they can meet all of their operating needs. 

When it comes to engines in medium-duty trucks, says Brian Tabel, executive director of marketing at Isuzu Commercial Truck of America, fleets are always looking for fuel efficiency to lower their cost of ownership. “If customers can have a truck that lowers fuel costs, it helps their bottom line,” he says. “That’s why we will continue to see changes, new technology developments and different engine types in the market.”

“Particularly in Class 6 and 7 medium-duty trucks,” relates Kevin Koester, Ford medium-duty truck and Super Duty fleet marketing manager, “we are seeing increased demand for gas engines due to the comparatively low maintenance they require compared to diesels with the latest emissions equipment. That’s one reason gas engines continue to gain acceptance in the market as a viable option for many lower-mileage applications.”

“We are committed to providing the right medium-duty engine technologies with an energy-diverse portfolio to meet the varying needs of customers, whether they want the benefits of diesel, the familiarity of spark-ignition, or the sustainability achievable with natural gas, hybrid or electric vehicles,” says Andrea Best, medium-duty product manager at Cummins. “There’s truly no single solution that meets needs across an entire market, but uptime and reliability are always at the forefront.”

At Hino, data indicates a downsizing of medium-duty engines for regional applications, relates Dominik Beckman, director of marketing and dealer development. “The nine-liter engine is positioned in the sweet spot of this shift,” he says.

Kelly Gedert, director of product marketing at Freightliner Trucks and Detroit Components, says that mid-range engines designed for medium-
duty trucks offer best-in-class fuel efficiency. “These engines also help medium-duty customers achieve maximum uptime,” she says. 

“For example, things like variable cam phasing enable more efficient aftertreatment system performance,” Gedert explains further. “With this technology in particular, at low engine speeds the exhaust timing can adjust to open the valves earlier in the operating cycle and cause warmer exhaust to be pushed in the direction of the aftertreatment system. That allows for more effective DPF regenerations, increasing uptime.”

Transmission changes

There is continued progress toward adopting fuel efficiency features and improvements in overall engine performance, according to Chad Semler, Navistar’s director of product marketing. “We also know that there are regulatory requirements coming in 2021 and 2024,” he says. “While we do not know the full impact of these changes yet, they will likely include transmission changes tied to fuel economy.”

Within the medium-duty market, automatic transmissions continue to dominate as manuals decline in popularity, mostly due to lack of driver experience but also due to improved fuel efficiency and productivity.

At Allison Transmission, for example, fully automatic transmissions feature Continuous Power Technology to support quicker route times and faster work cycles, higher average speeds and the need to operate medium-duty trucks more miles per day. The transmissions are also designed for low maintenance and extended service intervals so they can help improve uptime.

Advanced electronic controls are also part of the Allison portfolio of transmissions for medium-duty trucks. Those technologies, the manufacturer notes, support the engine and vehicle with operational features, and are continuously learning and adapting to road conditions and parameters.

Announced last year, Allison is developing a nine-speed fully automatic model for the medium-duty truck market. The new transmission will enhance fuel savings and help meet the next round of greenhouse gas emissions standards, the manufacturer says. 

The new Allison nine-speed will feature smaller steps for smoother starts and improved acceleration, the company reports. Additionally, a feature of the transmission that pick-up and delivery operations and package delivery fleets in particular may find valuable is an optional integral stop-start system that provides immediate engagement and vehicle hold while the engine is restarted. 

With the Procision seven-speed dual clutch automatic transmission for Class 6 and 7 trucks from Eaton Cummins Automated Transmission Technologies, the company says that fleets can expect to see eight to 10% better fuel economy compared to a torque converter automatic transmission. Featured as part of the Cummins Integrated Power portfolio, the Procision transmission is paired with the Cummins B6.7 engine for many North American Class 6 and 7 truck and bus manufacturers. 

Key features of the Procision seven-speed include Hill Helper & Hill Descent Control to prevent rollback or roll forward based on grade and vehicle weight and to allow for a controlled launch on hilly terrain. There is also a Creep Mode to enable low-speed parking lot and loading dock driving without applying the accelerator, and Tap Down Shifting so drivers have more control by downshifting on grades or in other conditions without removing their hands from the wheel.