Cummins, TM4 partnering for plug-in hybrid transit buses

Cummins, TM4 partnering for plug-in hybrid transit buses

Diesel engines to offer range extension for electric drivetrains.


Boucherville, Quebec, Canada; Columbus, Indiana – Cummins continues to push into new market spaces via partnerships. In the same week that it announced it would set up a transmissions joint venture with Eaton, officials said the diesel-engine specialists are working on a plug-in hybrid for Class 7 and 8 transit buses with Canadian electric motor company TM4 Inc.

The goal for the plug-in system would be a 50% fuel economy boost compared to conventional hybrid buses.

The hybrid system would include:

"Today, our customers can buy battery electric or hybrid buses with limited EV range. Our goal is to offer a system that can achieve 35km EV range and benefit from the 450kW fast charging infrastructure to recharge in less than 5 min. The range extender allows for peace of mind and significant flexibility,” said Robert Baril, managing director of TM4.

Cummins researchers will optimize the powertrain by selecting the engine with the best architecture to use as an electric commercial vehicle range extender, using the engine to manage the charge level of the all-electric drive battery pack. The range extender will be integrated, using advanced vehicle controls, with the electrified powertrain and other applicable technologies.

"The close integration and control of the electrified powertrain with an appropriately selected engine is critically important to developing a plug-in hybrid electric vehicle system. We believe that through the team's efforts we can become a significant player in electrification of commercial vehicles by providing complete systems to benefit our global customers," said Wayne Eckerle, vice president, Cummins Research and Technology.