Allison Transmission, IndyGo Partner on Next Generation Electric Hybrid Buses
The agency selected the company’s H 40 EP electric hybrid propulsion solution to power 27 new GILLIG buses and will be a lead fleet partner for Allison’s revolutionary new electric hybrid product, eGen Flex.

IndyGo will pair Allison’s H 40 EPTM with the Cummins B6.7 in 24 of the 27 GILLIG buses.
Allison Transmission
IndyGo and Allison Transmission are extending their long-standing relationship with the agency set to be the first transit to utilize the company’s new zero emission vehicle (ZEV)-capable electric-hybrid system, the eGen Flex.
The agency will pair Allison’s H 40 EPTM with the Cummins B6.7 in 24 of the 27 GILLIG buses. In addition, IndyGo, Allison, and Cummins are partnering to lead the charge in innovative propulsion solutions by integrating Allison’s new electric-hybrid propulsion system, the eGen Flex into three of IndyGo’s new buses. The eGen Flex Max specified by IndyGo will enable pure electric (engine off) operation for up to 10 miles on any route, at any time, without capital infrastructure investment in charging stations. The eGen Flex system is Allison’s initial product offering under its recently announced eGen portfolio of electric and hybrid electric propulsion solutions.
“This partnership with Allison lays the foundation for future collaboration as we jointly advance clean air propulsion and emphasizes our commitment to a clean fleet to improve the greater Indianapolis community and reduce our carbon footprint,” said Inez Evans, IndyGo President/CEO. “IndyGo is in the business of moving people and the decision to choose Allison electric hybrids directly aligns with IndyGo’s mission in providing safe, reliable, and accessible mobility options to Marion County.”
The eGen Flex system can improve fuel economy by up to 25% versus a conventional diesel bus, and it can operate accessories such as air conditioning and electric heat at their optimal efficiency with clean and quiet electric power. Moving these accessories to electric power also reduces the strain on the engine. These capabilities combine to reduce fuel consumption and maintenance costs. The eGen Flex can also eliminate engine emissions and noise while loading and unloading passengers, in dense pedestrian areas, and in zero emission zones and bus depots, enhancing quality of life. The electric vehicle operation in zero emission zones and bus depots using geo-fencing reduces fuel consumption and CO2 emissions, helping to protect the environment.
eGen Flex and eGen Flex Max will be offered in CertPlus model configurations for sale in California Air Resources Board (CARB)-adopting states. Like the existing H 40/50 EP nomenclature, eGen Flex and eGen Flex Max will also be available in "40" and "50" configurations, based on fleet torque requirements.
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