The Kia Sportage will be the first model in the company’s line-up to benefit from a new diesel mild-hybrid powertrain option.

Wearing the firm’s EcoDynamics+ badge, the new system will use a 0.46 kWh 48-volt lithium-ion battery plus a mild-hybrid starter-generator (MHSG) connected to the diesel engine’s crankshaft via a belt.

An inverter allows the MHSG to switch between acting as a generator and a motor.

For instance, during acceleration the MHSG provides up to 10 kW (13hp) of assistance, but can also reduce engine load in other driving circumstances in order to reduce fuel consumption.

During deceleration, the unit acts as a generator, replenishing the batteries via energy recuperation.

In some situations, the diesel engine can be switched off completely, with the MHSG restarting it almost instantly when the driver presses the accelerator.

Kia claims the system can reduce CO2 emissions by up to 4% (measured on the new WLTP test procedure) and adds minimal weight to the vehicle.

In fact, the system allows some other components to be down-sized to offset this – a smaller conventional starter motor, for instance, and a reduced capacity 12v battery.

The small 48v battery pack can be easily integrated under the boot floor of most vehicles, and the system is compatible with both manual and automatic transmissions, as well as two- and four-wheel-drive layouts.

Although Kia intends to initially introduce the mild-hybrid system in combination with a diesel engine, a version adapted for petrol powerplants will follow.

The new EcoDynamics+ mild-hybrid system is expected to arrive initially in the Sportage later in 2018, followed by the new Kia Ceed in 2019.