Mild hybrid

A mild hybrid bus uses a small electric motor to assist the diesel engine during start-up, acceleration, and braking. The electric motor does not drive the bus independently but works together with an energy recovery system and a start-stop function that shuts off the engine when stopped and restarts it when moving again.

The electrical system operates at low voltage, typically around 48 volts, and employs a small battery or ultracapacitors charged exclusively through regenerative braking, without external charging. This setup helps reduce fuel consumption and emissions, especially in urban environments with frequent stops.

Although these buses cannot run solely on the electric motor, many manufacturers market them as standard "hybrids", and in some regions, they may qualify for government subsidies aimed at environmentally friendly vehicles.

Usually, mild hybrid systems are offered as optional features on specific bus bodies without significant structural modifications, so it is rare to see distinct model designations in technical documents or VINs.

Visually, these hybrids can often be identified by the presence of a "box" housing the battery or capacitors.

MAN EfficientHybrid

Mercedes hybrid

Setra hybrid