Kia will significantly increase its range of hybrid cars in the next few years to meet ever more stringent fuel economy and emissions regulations around the world.

The first of these new hybrids will be in next year's new Optima saloon, code-named JF. The new Optima will eventually be sold with hybrid and plug-in hybrid powertrains as well as petrol and diesel combustion engines.

And the Koreans are working on a Toyota Prius rival for launch in 2016 which is a "dedicated hybrid" based on a new platform.

The current Optima is available as a petrol-engined car or a hybrid in America, and is manufactured there as well as in Korea. US sales run at around 160,000 a year.

A different Optima hybrid is offered to European customers, but has never been available in the UK because of the dominance of diesel.

Kia is also making big efforts on interior trim quality with the new Optima, and talks about JF in the same breath as BMW and Mercedes-Benz.

The company has shown an interior buck of the car, without allowing photography, at its R&D centre in Korea, and it is clearly influenced by the uncluttered, horizontal dash structures typical of BMW.

The exterior detailing has taken a step forwards, too. In size the new Optima is the same the present model, to within a millimetre or two.

The Prius rival, code-named DE, sits between the B and C segments at 4.3 metres long. The significant thing is that it looks like a cross between an SUV and a hatchback, unlike the Prius and Honda Insight, whose designs were largely influenced by aerodynamics.

Kia says it asked potential buyers what they dislike about current hybrids, and design came top of the list. At a customer clinic in the UK there was overwhelming approval for DE as long as the fuel figures are competitive. Kia is targeting a minimum 50mpg (US) and is currently debating what to aim for over CO2 emissions.

The car will initially be sold as a normal petrol hybrid with a 1.6-litre Gamma engine, but a plug-in hybrid is under consideration for later, as are other models using the new platform.

Importantly, its size leaves room for a B-segment SUV, which Kia has admitted it needs, to slot in underneath DE.