Ken Gratton•3 Oct 2012

NEWS

Kia's multi-pronged powertrain plans

The whole world's downsizing and hypermiling, but the Koreans are placing their bets each way

The Hyundai/Kia Automotive Group is embarked on an ambitious program to reduce fuel consumption and emissions across its global product range – just like every other car company around the world.

But while the two Korean brands are jointly committed to development of fuel cells, electric vehicles, LPG-fuelled cars and hybrids, there's still plenty of life left in the conventional internal-combustion engine. In fact, the automotive group is still working on the Tau V8 that powers Hyundai's Genesis, according to Doctor Joachim Hahn. Kia's chief drivetrain boffin in Europe was interviewed last week by Australian journalists at the Paris motor show.

"The development on that engine is not yet stopped," Dr Hahn replied to a question concerning the lifespan for the V8. "That is nothing that we in Europe are focusing on, but I know that recently it has been changed from port fuel injection to direct injection. Also for the V8, things like charging [forced induction] are under investigation."

While the V8 engine is of little consequence in Europe, where even the company's Lambda V6 is considered overkill, Dr Hahn sees the value in having such an engine for North America – the traditional home of the production V8.

"I think besides technical reasons with the focus on efficiency there is still some market, which is highly emotionally driven. There is no wrong or no right. I appreciate [having] more sports-driven models and I don't fear that this will have a strong impact on our fleet emissions.

"In Europe... from 2015 on, there will [be] some penalties if you do not reach your level. We are convinced that we will [achieve] the 130 grams [per kilometre standard]. We don't want to pay any penalty, but even introducing some fun-to-drive vehicles I'm pretty sure will not have a big influence, because you have to multiply the CO2 output with the sales numbers for each vehicle."

And Dr Hahn has a user-pays view of the world, where big bangers and their owners are concerned.

"With the top-end vehicles you can earn a lot of money," he said, eliciting laughs from the journalists. Clearly Kia and its parent, Hyundai, would charge V8 drivers something extra to cover the anticipated financial penalties if the two companies' emissions figures – averaged across the new-car fleet – should remain above 130g/km beyond 2015.

Dr Hahn, however, is confident the two companies will manage to sneak in below that threshold, due to a variety of reasons. For a start, every V8-engined Hyundai or Kia sold beyond 2015 is likely to be matched by a fuel cell vehicle, a hybrid or an EV. Even cars and light commercials with conventional drivetrains won't necessarily be the profligate beasts they are today. Downsizing is already under way in the Hyundai and Kia ranges.

"We see that the customer is still willing to accept smaller engines, so in future you'll see more downsizing," explained Dr Hahn. "I don't know how valid this is in Australia, but in Europe it works very well. The reduction in the number of cylinders is not an issue anymore."

One example of downsizing in action provided by Dr Hahn was the American Optima, which has recently exchanged a Lambda V6 for a direct-injected and turbocharged Theta four-cylinder, displacing two litres.

"In some markets where the V6 was very popular... not so much in the European market... but in North America we replaced it with the turbocharged four-cylinder – and not as an option... but as the only available powertrain. The Optima K5 is not available anymore with the V6, but as far as I've heard from some critics in the US, the reception of that model is even [better] than the previous V6.

"Personally I drove this vehicle – it's nice."

The four-cylinder's character (with the turbocharging to bolster torque as well), makes it livelier and easier to drive than the V6 Optima. Dr Hahn explained that four-cylinder engines of around two litres deliver the ideal swept volume for early torque pick-up and a wide swathe of torque across the rev range.

"We have a better single-cylinder displacement," he explained. "So if we have a two-litre four-cylinder, for example, it's nice to have this displacement of about 0.5-litre displacement per single unit, which enables us to deliver torque earlier than with a V6 on the same level of displacement. The smaller number of single cylinders delivers the torque earlier than on a comparable six-cylinder."

Asked how the smaller turbocharged Theta compared with the naturally-aspirated 2.4-litre Theta powering the Optima in Australia, Dr Hahn gave the nod to the smaller engine.

"Although it has only two-litre displacement, with the turbocharging it's much better."

Unfortunately, the Optima Turbo is built in left-hand drive only, which means we won't be seeing it in Australia. Nor will we see the Optima Hybrid, which is built in two different plants (one in North America, the other in Europe) and neither of them building right-hand drive versions – so cross that off your list too. There are no technical reasons why the Optima isn't built for right-hand drive markets such as Australia and the UK, according to Dr Hahn. It's simply a matter of finding the buyers in sufficient numbers to justify the development expenditure. With the slow take-up of hybrid vehicles in Europe – and the UK being a small component of the European market – the business case for a right-hook Optima Hybrid is unsustainable.

"I can only assume so far that it is more a sales discussion, because from the package, the e-motor [electric motor] in our Optima [Hybrid] is of the same size as the torque converter of the automatic six-speed... so package-wise it should not be an issue."

Kia is yet to reveal what the Optima Hybrid will cost in Europe, so Dr Hahn was coy about providing any indication of the premium payable over the conventional Optima trimmed to the same level.

"We will see in a few weeks..."

He was much more forthcoming about the car's technical make-up and why it makes sense – as long as the market for it is strong enough.

"[The European Optima Hybrid] is not identical to the version that is on sale in the US market. We have a different combustion engine; we are using the so-called 'Nu' engine family – a newly-developed 2.0-litre engine, in that case. We have to say 'family', because meanwhile this engine is available as a GDI, for example in the new Carens. It is available as an MPI – as we call it – so port-fuel injection – and it is available as a CVVL in some markets – with continuously variable valvetrain.

"[For] The hybrid, we are using a specific version... it is running with an Atkinson cycle. So it is running with an extremely late intake closing... this engine in a conventional car I assume you would say it is a poor powertrain [with] somewhat low torque. But the benefit of the Atkinson Cycle is the high efficiency..."

Toyota also relies on the Atkinson Cycle for the engines powering that company's various hybrid-drive models. Atkinson is practically synonymous with hybrids, for the reasons given by Dr Hahn.

"This combination of Atkinson Cycle with the e-motor, which by nature [produces] its torque from zero [rpm], is a nice combination... You don't suffer from the Atkinson Cycle, but you have the benefit from it in terms of part-load fuel consumption."

It's thus in the nature of petrol engines – running on the Atkinson Cycle in particular – to complement the electric drive systems of hybrids, but what about diesels? Peugeot has been experimenting with diesel engines in hybrid-drive systems, and Hyundai/Kia's R Series diesel is a thoroughly up to date powerplant that could lend itself to that sort of application. Once again, however, cost will be a major factor, says Dr Hahn.

"There is the potential; the question is more price-related, because the diesel engine is already more expensive than the gasoline engine.

While the R Series has been around for a few years, it is not being placed on a shelf and left to stagnate.

"We are now introducing in the Sorento the so-called low-pressure EGR, so that we are using residual gas for the combustion engine to reduce NOx," said Dr Hahn. "Now with this engine... it means we are not taking the residual gas upstream from the turbocharger, but downstream, which delivers us more efficiency, better response from the vehicle – and also that is beneficial for the engine. As soon as we achieve a higher level of low-end torque we have the opportunity to use longer gear ratios. Longer gear ratios always means a shift of operating point and [that] is beneficial to fuel consumption. So... there is a continuous improvement process also on an existing engine."

Hyundai/Kia's in-house transmission development means those longer gear ratios could happen sooner rather than later. The group already has an eight-speed automatic, which has been developed first and foremost for the Lambda petrol V6, but there's no reason it couldn't work its way into a diesel-powered SUV down the track. Dr Hahn also mentioned that the two Korean brands are working on a development of the existing dual-clutch transmission to handle high-torque engines (up to 350Nm). But one type of self-shifting transmission we are unlikely to see from Hyundai/Kia is the continuously variable transmission.

"So far – from the driveability [perspective] – we are quite happy with the solution we have. So we are not planning to have a CVT," he said.

All this driveline tech development is happening in the present, with some engines and transmissions expected to roll out to the public within 12 months, but Hyundai/Kia's work on fuel cells is more like pie in the sky. While Hyundai has just announced it will build 1000 units of the ix35 fuel cell vehicle by 2015, it's a small-scale commitment by the standard of typical series production numbers. Dr Hahn insinuates that infrastructure remains a vexing problem for manufacturers of fuel cell cars.

"We have fuel cell cars driving around; this technology exists... [but] Even from our development activities in Germany, we know about the effort to fill up that car. First you have to contact companies; is your filling station currently working? And from time to time they say: 'The next six weeks we have maintenance; you can't fill up the car'.

"This is, technically-wise, nothing that cannot be solved, but still, there is no grid existing and the customer will not buy it..."

Electric vehicles don't necessarily provide a ready solution either, according to Dr Hahn.

"I have some concerns. That is always following the approach that anyway, in the end, we will have a pure electrical drive, which technically I think it's an approach I can understand. But so far it does not answer the question where does the energy come from?

"The purely electrical drive is not worth anything if, in the beginning of the chain [you] fire the same hydrocarbons that you do today... And then, if you do so, maybe the chemical storage in a battery is [no more] efficient than the chemical storage in hydrocarbons as we know today. Because that is easy; that is known by physics... the [energy] density is extremely good."

Dr Hahn may have misgivings about the present viability of the advanced drivetrain systems Hyundai and Kia are currently developing, but clearly the two companies are just as committed to the emerging technology as their existing drivetrain systems. Once the technology and infrastructure pre-requisites have gained sufficient ground expect Hyundai and Kia to be right at the forefront of the industry, marketing the right vehicles to suit future needs.

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Kia's multi-pronged powertrain plans

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