Kia unveiled its revamped fourth-generation Rio hatchback recently, which is admittedly news that’s unlikely to make you sit up and take note.
However, among the myriad upgrades the Rio received – ranging from more efficient engines to a bolder-looking exterior – was one addition of particular note: a clutch-by-wire system.
The newly adopted technology, which was developed at the Hyundai Motor Europe Technical Centre in Germany, is part of a new “intelligent Manual Transmission” option.
It’s offered in the new Ecodynamics+ version of the Rio and, in the Kia's cabin, you'll find a conventional gear stick and three pedals. The iMT's clutch pedal, however, does not interact directly with the clutch itself; there is no hydraulic connection, no mechanical linkage or a Bowden cable between the two.
Instead, signals are taken from the clutch pedal assembly and used to control the clutch with a separate electrohydraulic system – which, while sounding like an unnecessary complication, can offer benefits for both the manufacturer and the driver.
From the get-go, the system is easier to integrate into a car’s design as there is no need to worry about routing pipes or linkages. It’s also much less complex to assemble on the production line, which reduces construction time and costs.
Such a system can also deliver repeatable and smooth engagement while accounting for wear, making it easier to use than a conventional set-up. How clutch-by-wire systems work is relatively straightforward, too – which could help on the maintenance and reliability front.
A clutch-by-wire system additionally grants automated clutch operation in certain instances, allowing for improvements in efficiency. For example, as is employed by the Kia, the clutch-by-wire system can be used to permit automatic engine-off coasting.
This, in the case of the new Rio Ecodynamics+, is reputed to improve its fuel efficiency and cut its CO2 emissions by three per cent. It isn’t much but, in this day and age, every fraction counts due to increasingly stringent emissions regulations.
While manual transmissions are an increasingly rare option in some markets, there are areas where they remain prominent due to their lower costs. Additionally, manual gearboxes are straightforward and often lighter than more expensive alternatives such as torque converter-based automatics and dual-clutch transmissions – so improving their capabilities while retaining their inherent strengths is a sensible move.
Some may recall some old semi-automatic transmissions that appear similar in concept, such as the Saab Sensonic, Volkswagen Autostick or the Valeo option found in the Ferrari Mondial. Unlike the Kia iMT, however, those didn’t have a clutch pedal.
You might subsequently wonder why the company has bothered retaining the clutch pedal at all – but there is one prominent reason: driver involvement.
Dr Michael Winkler, head of powertrain at the Hyundai Motor Europe Technical Centre and responsible for the development of the system, said: “An automatic or a dual-clutch transmission suits a lot of drivers, but European drivers in particular still love changing gear for themselves. Alongside the increasing demand for electrified models, the iMT is a result of us exploring ways to electrify the 'classic' manual transmission.”
That said, Hyundai – Kia's parent company – and Kia itself will be deploying versions of the iMT without a clutch pedal in some markets; this will prove beneficial for those who regularly drive in heavy traffic, as no manual clutch operation will be required at all.
In either case, there are other potential avenues of exploration. For example, aside from making the integration of hybrid technologies easier, a clutch-by-wire system coupled to an adaptive cruise system could allow for automated creeping in traffic. An entirely electromechanical version would also do away with the need for fluid, making it more environmentally friendly due to the absence of toxic hydraulic fluid.
“We want to continue providing drivers with a familiar and engaging manual gear change,” said Winkler, “so this is an ideal solution for the new range of mild-hybrid powertrains we are rolling out across Europe in the months ahead.”
Some may understandably gripe about the removal of yet another aspect of direct interaction with a car. It's worth remembering, that said, that the vast majority of mainstream buyers don't have issues with technologies such as electronic power assistance and electrohydraulic braking systems – or instrumentation that’s so heavily biased that it rarely presents a true account of what’s going on.
Many also quickly become acclimatised to the new technology and begin to appreciate the range of improvements on offer. This is particularly the case when such systems are executed in such a fashion that they don’t detract from the driving experience.
Regardless, it’s pleasing to see that development of manual transmissions remains ongoing; efficiency-boosting technology such as this may mean your next car is still offered with a manual option, after all, instead of only with an automatic transmission.
Keyword: Why Kia is introducing clutch-by-wire systems