Kia is set to introduce its first 48V diesel mild-hybrid powertrain sometime in the second half of this year. The EcoDynamics+ system, as it is called, features an additional 0.46 kWh 48 volt lithium-ion battery and a new mild-hybrid starter-generator (MHSG) unit.

Connected by a belt to the diesel engine’s crankshaft, the system offers two modes of operation, motor and generator, switching being electronically controlled. Under acceleration, the MHSG provides up to 10 kW (13 hp) of electric power assistance to the powertrain in motor mode, providing additional torque and improving performance under hard acceleration, or reducing engine load during light acceleration.

Under deceleration, the system switches to ‘generator’ mode, recuperating energy from the crankshaft to recharge the battery while on the move. Battery power can also be used to provide a new Moving Stop & Start function. If the battery has sufficient charge, the diesel engine turns off automatically during in-gear deceleration and braking, seamlessly re-igniting when the driver presses the throttle pedal.

The automaker says the system will help reduce CO2 emissions, lowering this by up to 4% on the new worldwide harmonised light vehicles test procedure (WLTP) and 7% on an NEDC calculation.

Compact packaging means the system easily integrates into existing architecture. In most applications, the 48V battery will be located beneath the boot floor, minimising the impact on vehicle practicality. As for the MHSG, since it integrates directly with the engine, there will be little need to repackage the engine bay.

Additionally, a DC/DC converter enables the 48 volt battery to connect to the vehicle’s on-board power supply, leading to a significant reduction in the size of the 12 volt battery required to power the car’s ancillary electronics. The adoption of the MHSG also means the conventional starter motor can be downsized and used primarily for cold starts at low temperatures, and charge from the 48V battery can help start the engine in most conditions.

The EcoDynamics+ mild-hybrid system is compatible with both manual and automatic transmissions, and can work on any type of drivetrain layouts (front-, rear- and all-wheel). Diesel isn’t the only route either, the company says, because it can be adapted for use in gasoline engines.

The Kia Sportage facelift will be the first model to offer the new EcoDynamics+ diesel mild-hybrid powertrain later this year. The second model to get the system will be the third-generation Kia Ceed, from next year.