Kia details its new clutch-by-wire intelligent Manual Transmission for mild hybrid petrol, diesel powertrains

Kia has revealed more details about its new intelligent Manual Transmission (iMT), which uses a “clutch-by-wire” system for use in a range of mild hybrid vehicles. The transmission has already been introduced to the 2020 i30 and Rio facelifts, and will soon make its way to other models with the latest mild hybrid petrol and diesel engines.

These include the Ceed in Europe, which will gain new EcoDynamics+ variants, powered by a 1.6 litre CRDi diesel engine. Later in the year, other Kia models, with a range of new engines and mild hybrid powertrains will adopt the transmission as well.

Instead of a mechanical linkage, the clutch on Kia’s iMT uses an electronic wired connection integrated into the 48-volt mild hybrid system and works with the mild-hybrid starter-generator (MHSG) unit.

The benefit here is ability to switch off the engine earlier than Kia’s Idle Stop & Go start-stop system when coasting to a halt. This improves overall fuel efficiency and can reduce CO2 emissions by around 3% in real-world driving conditions.

On a step-by-step basis, when a driver is coming up to a corner or junction, he or she can leave the car in-gear as it starts to coast, gently slowing the car down. The iMT detects this and sends an electronic signal to the gearbox and MHSG to seamlessly switch off the engine and decouples the clutch.

With the engine switched off, the car will continue coasting, with the open clutch limiting deceleration and allowing the car to make the most of its kinetic energy. When the driver pushes the accelerator to pick up speed, or engages the clutch to change gear, the MHSG restarts the engine in the driver’s selected gear, or in neutral (with an open clutch).

At this point, electric power from the MHSG and 48-volt battery brings the engine and transmission up to the correct speed. Should the car drop below a certain speed, the engine restarts with assistance from the mild hybrid system, and the clutch closes, to avoid labouring the engine in the engaged gear.

Kia says the clutch pedal operates in the same manner as a conventional manual, but with greater controllability due to the electromechanical control of the clutch and a “biting point” that enables drivers to change gears smoothly.

It adds that the technology is necessary despite automatic or double-clutch transmission suiting most drivers, as a good number of its European customers (around 50%) are still fans of the manual.