You might recall the recently-updated Kia Rio comes with an all-new mild-hybrid powertrain, featuring a fancy piece of new tech called Intelligent Manual Transmission (iMT) that promises improved fuel efficiency without eliminating driving engagement.
For most people, the appropriate response is probably nothing more than “oh, that’s cool”. But for the few car nerds like you and I, we were left wondering how exactly this curious piece of technology work. Well, wonder no more because Kia has now released some juicy details about the clutch-by-wire manual transmission system for us to pore over – so lets dive right in.
Unlike a traditional gearbox with a mechanical linkage, the iMT uses an electrical connection between the clutch pedal and the clutch plate. When the car is coasting in anticipation of a corner or slow down, the electrical system automatically sends a signal to shut off the engine and disengage the clutch to reduce speed loss.
As the driver depresses the accelerator again to pick up speed, the powertrain will immediately spring back to life in the selected gear, or in neutral if the driver depresses the clutch pedal or the engine speed is too low for the selected gear. In the latter case, the mild-hybrid starter-generator and 48V battery will automatically bring the engine and transmission up to the right speed before coupling the clutch.
Kia claims that the clutch pedal on the iMT operates in the same manner as conventional manual gearboxes, but with greater controllability due to the electromechanical control of the clutch, and a ‘biting point’ that enables drivers to change gears smoothly.
As a result of shutting off the engine earlier (compared to the standard idle start-stop system), Kia says that the improved overall fuel efficiency can reduce carbon dioxide emissions by around 3% in real-world driving conditions.
The iMT is developed fully in-house by parent company Hyundai, at the Hyundai Motor Europe Technical Centre in Offenbach, Germany. The same transmission is also used in several new Hyundai models, such as the all-new i20 and i30 facelift.
Kia’s Head of Powertrain, Dr Michael Winkler who oversaw the development of the iMT, said: “We are always looking at new ways to improve powertrain efficiency and performance, and the iMT is one such innovation. An automatic or a dual-clutch transmission suits a lot of drivers, but European drivers in particular still love changing gear for themselves.
“We want to continue providing drivers with a familiar and engaging manual gear change, so this is an ideal solution for the new range of MHEV powertrains we are rolling out across Europe in the months ahead,” Winkler added. “Alongside the increasing demand for electrified models, the iMT is a result of us exploring ways to electrify the ‘classic’ manual transmission.”