The Optima T-Hybrid combines the existing 1.7-litre turbo diesel four-cylinder engine offered in the mid-size sedan in the European market with a 48-volt lead-carbon battery, electric motor and electric supercharger.
The mild hybrid setup isn't like many full scale hybrid systems - such as that seen in the Toyota Camry Hybrid, for instance - however it is said to allow the Optima T-Hybrid to drive in "electric-only mode at low speeds and wheel cruising", using kinetic energy capturing technology to recharge the car's battery pack.
According to Kia the car uses lead-carbon batteries rather than lithium-ion batteries as no active cooling is required, and the company claims they are more easily recycled at the end of the lifecycle.
A new stop-start system with a belt-driven generator takes the place of the standard alternator, "meaning the engine can restart with almost no noise of vibration" according to the company. There's also a new electric supercharger for the diesel engine that is said to improve power and torque at all engine speeds, particularly down low in the rev range.
No power, torque or fuel economy figures have been made available for the new drivetrain, but the company says a power increase "of between 15 to 20 per cent" is likely, which would see the 100kW/320Nm 1.7-litre diesel - which is offered only in the Rondo people-mover in Australia - gain a welcome dose of extra punch. Theoretically, it could boost the outputs to 125kW and 385Nm.
Kia Australia general manager of corporate communications Kevin Hepworth told CarAdvice that no timing for implementation of the new drivetrain has been made public at this stage - indeed, the official line from the brand is that "the T-Hybrid powertrain remains under consideration for new Kia models in the future".
However, Hepworth indicated that the fact the drivetrain has been showcased in the current Optima could give something away about where a potential new powertrain option for the all-new Optima due to be uncovered in 2015.
"If a diesel-hybrid were to be available in the new-generation Optima, we'd likely have a look at it," he said.
"We've got hybrid on the table again now - we're looking at it," he said, though Kia Australia currently offers no hybrid variants of any of its models.