A PETROL mild-hybrid powertrain has been developed by Kia and will make its debut on a revamped version of the Rio supermini due for release later in the year.

The 48-volt system is joined by an all-electric clutch-by-wire set up which eliminates mechanical linkages and aids stop/start and overall fuel efficiency.

Kia says that the new mild-hybrid system - mated to a 1.0-litre Smartstream engine - reduces CO2 emissions by between 8.1 and 10.7 per cent with power outputs of either 100 or 120ps.

Both 48V powertrains will be equipped with a Drive Mode Select system, giving drivers the choice to customise their drive with ‘Eco', ‘Sport' and ‘Normal' modes.

The new powertrain means that Kia now has 48-volt mild-hybrid systems available on diesel and petrol models.

The current Rio - which was launched in 2017 - is also being refreshed with subtle changes front and rear to enhance its looks while on the inside the changes are more significant.

As well as new high-tech driver assistance and safety features including Lane Following Assist, Smart Cruise Control, Forward Collision-Avoidance Assist, and Blind-Spot Collision-Avoidance Assist the car also has an upgraded infotainment system featuring an eight-inch touchscreen display and Kia's latest UVO telematics system.

There's also a higher-resolution 4.2-inch digital display in the driver's instrument cluster.

LED headlights with integral daytime running lights are now standard across the range while other engines in the line up have also been upgraded to reduce emissions and improve efficiency.

The 100ps 1.0-litre T-GDi engine is now offered with a six-speed manual transmission, replacing the earlier five-speed manual, and Kia's seven-speed auto dual-clutch transmission.

The car's stop/start system has also been improved to work when both the brake and clutch pedals are depressed as the vehicle comes to a halt. Previously the system was linked exclusively to the clutch.

Official performance and efficiency figures for the upgraded Rio's new powertrains will be announced nearer to the car's on-sale date which is expected in the third quarter of the year.

Emilio Herrera, chief operating officer for Kia Motors Europe, said: "The Rio is an important car for Kia in Europe and worldwide, and is an entry point into the Kia brand for many drivers. The upgraded model builds on the car's key strengths - practicality, quality and technology - with newly electrified powertrains, a refreshed design, and advanced safety and telematics features often found in cars many segments above. We are convinced these upgrades will make the Rio more successful than ever."

As with all other Kias the Rio is sold with the brand's industry-leading 7-Year, 100,000-mile warranty as standard. Prices for the new model are still to be announced but the current range costs from around £12,500.