Powerful and Efficient: the Drive System

• Two drive concepts for two vehicle worlds: electric portal axle and central motor
• MMTI: brake and drive as one system
• Efficiency as a central development objective

The new city bus generation also consistently follows the path of an electric vehicle that has been developed from the ground up for battery operation. Depending on the vehicle variant, two different, coordinated drive concepts are used, complemented by a new system that controls brake and drive as a single unit for the first time.

Two Drive Concepts for Two Vehicle Worlds: Electric Portal Axle and Central Motor

The low-floor version of the next-generation eCitaro uses the AxTrax 2 LF electric portal axle with wheel-near electric motors. With a system output of up to 360 kilowatts, the new drive axle is significantly more powerful than the axle installed in the current eCitaro, which has a peak output of around 280 kilowatts. The additional power not only improves gradeability and acceleration when fully loaded. In city traffic with frequent stop-and-go operation, it also ensures more efficient energy use and therefore lower energy consumption and greater range. In addition, for the articulated bus, the power of a single drive axle is sufficient, which is why Daimler Buses offers the articulated version with only one drive axle. This simplifies the drivetrain and saves additional weight. Because the axle is so compact, space is also available at the rear for a continuous flat floor without reducing the wheelchair area at door 2.

The low-entry (LE) version, by contrast, uses a central motor in combination with the Mercedes-Benz RO 440 rear axle. This drive combination enables speeds of up to 100 km/h and therefore qualifies the next-generation eCitaro for both urban scheduled service and interurban operation.

At the front, as in the current eCitaro, an independent wheel suspension is used, allowing for a wide central aisle. The low center of gravity, achieved with four battery packs in the underfloor area, helps elevate the driving characteristics, driving safety, and ride comfort of the new vehicle generation to a new level. Even greater ride comfort can be achieved with the optional electronically controlled damping system, which automatically adapts to the respective payload and reliably prevents excessive rolling and pitching movements

MMTI: Brake and Drive as One System

With the new MMTI (Modular Multi Torque Interface) system, Daimler Buses introduces wheel-specific control of drive and braking in its new city bus generation. Thanks to a control unit, the system regulates situationally and in real time for each individual wheel whether energy is recuperated or mechanical braking is applied. This extends usable recuperation phases, reduces wear on the mechanical brake, and simultaneously increases driving stability. As a result, brake and drive work together for the first time according to a common logic developed by Daimler Buses itself.