Drive Unit
Inverter
Rechargeable Energy Storage System
Proven Electric Hybrid Solutions
These approximate figures represent the eGen Flex's impact around the globe, as of 2024.
Impact of Allison's Electric Hybrid Propulsion Systems
Inside eGen Flex®
Drive Unit
Featuring a multispeed gearbox with fully integrated electric motors built in, the drive unit provides propulsion while the engine is at zero speed, enabling full engine-off propulsion capability.
Inverter
Designed to improve vehicle efficiency and save space, Allison reduced the inverter to be one-third the weight and half the footprint of earlier generation electric hybrid systems.
Rechargeable Energy Storage System
eGen Flex® uses lithium-titanate (LTO) battery chemistry to support EV operation. The electric battery is recharged through a regenerative braking system, enabling storage of energy caused by the friction from braking that would normally be released as heat.
Reduced Dependence on Fossil Fuels
Fleets that operate eGen Flex® can expect improved fuel economy of up to 25% compared to conventional diesel buses. The system’s electric battery is recharged through a regenerative braking system, eliminating the need for charging infrastructure. It also allows the vehicle to operate accessories, such as air conditioning and heat, at optimal efficiency with clean and quiet electric power.
Increased Vehicle Uptime
eGen Flex® eliminates inefficient belt-driven accessories and decreases the load on the engine. The regenerative braking system reduces brake wear and increases power to the wheels. In addition, the inverter utilizes WEG cooling, eliminating oil coolant lines from the drive unit. These factors all contribute to reduced costs for vehicle integration and maintenance.