The new powertrain, which is the key upgrade alongside the design changes, comprises Kia's ‘Smartstream’ 1.0-litre T-GDi turbocharged petrol engine and a 48V electrical system.
These enable the Rio to offer electric torque assistance and regenerative braking, maximising fuel efficiency. This differentiates the Rio from most superminis, which are yet to receive mild-hybrid technology.
Further setting the Rio apart is the introduction of Kia’s Continuously Variable Valve Duration (CVVD) technology, which enables the engine to switch between different combustion cycles depending on load to maximise efficiency, and a new clutch-by-wire intelligent manual transmission.
This latter innovation means there's no mechanical connection between the gearstick and gearbox and clutch - believed to be a market first. It's said to contribute to the mild-hybrid powertrain's greater fuel efficiency while maintaining the driver engagement of a conventional manual gearbox.
These upgrades also increase performance over the Rio’s previous ‘Kappa’ 1.0-litre T-GDi engine, with a 16%-higher peak torque output.
Peak power, however, is unaltered, for the Smartstream engine produces the same 99bhp or 118bhp as the unit it replaces. Full performance figures will be announced at a later date.
As well as the new mild-hybrid system, the Rio now offers a choice of Smartstream petrol engines: the 98bhp 1.0-litre T-GDi and a new version of Kia’s 83bhp naturally aspirated 1.2-litre unit.
The former is also now offered with a six-speed manual gearbox, replacing a five-speed manual, and a seven-speed dual-clutch automatic.