Kia pins hopes on downsizing

There's a gradual convergence of ideas and strategies for the development of the internal combustion engine over the next few years.

With fuel cells and EVs still some way off as viable solutions to the world's transport problems -- peak oil production and global climate change primarily -- engineers working on internal combustion must stretch the old technology to meet the demands of the next 10 years or more.

One of those engineers with a very clear view on how that need will impact on car companies -- and his employer in particular -- is Doctor Joachim Hahn, head of powertrain engineering, design and testing at Kia's European Technical Centre.

Dr Hahn, speaking with the Carsales Network during the Geneva motor show last week, discussed Kia's need to assemble technical solutions to suit different world markets and different buyer types within those markets. In the first example, downsizing engine displacement in the US doesn't mean the same thing as it does in Europe. The second exampled offered was the high-tech induction technology that is more readily introduced in an upmarket model, which can absorb the cost of the technology better than a basic entry-level car such as the company's Picanto.

But some means are already available to the company to benefit the consumer and the environment -- and can be readily bolted into very affordable cars. The turbocharged Kappa three-cylinder engine that will eventually make its way into the new Picanto is one such example. Turbocharging is a cost-effective way of improving driveability and leaving the way open for engines to post frugal consumption figures.

"Turbocharging is clearly on the road map for us," said Dr Hahn. "We have already started production of turbocharged engines... the Theta 2.0-litre engine is already under production with turbocharger and also... with the combination of turbocharging and direct injection -- which is really very beneficial."

Kia's turbocharged Theta engine may come to Australia under the bonnet of the Optima mid-size sedan.

"We will see this combination of technology coming also in other displacements and class in the near future in the Hyundai Motor Company -- for Kia as well as for Hyundai," Dr Hahn continued.

"Still, we always have to answer the question 'what is the most reasonable -- the best -- configuration for the different segments...?'

"It is not necessarily the same technical answer for all segments. Something that can be ideal for a D segment car is not necessarily the best for an A segment [car], because the cost situation is different."

Out of curiosity -- and since the engine may yet power the Optima in Australia -- we asked Dr Hahn how the smaller 2.0-litre turbo engine shaped up against the 2.4-litre naturally-aspirated GDI engine.

"It's much better," he replied. "As far as I know, the Theta turbo GDI has 270 horsepower. From the torque curve, it's much more impressive than the naturally-aspirated [engine]."

The Theta with forced induction is a little like having one's cake and eating it too. Based on Dr Hahn's remarks, it should provide improved performance and driveability in the Optima, but with the advantage of lower fuel consumption when the car is being driven sensibly.

In our local launch review of the Optima, the point was made that if the new sedan lacked for anything at all, it was torque. The current 2.4-litre GDI engine is a peaky powerplant for such a relatively large and heavy car. An engine like the Theta turbo could make the Optima a very appealing car indeed; either that or a turbodiesel, to achieve much the same ends, which leads to the question: Is it petrol or diesel that offers the greater long-term potential for performance and fuel efficiency?

The Kia engineer doesn't directly answer the question, but states his view that two-stage turbocharging has been used with diesel induction to boost power in the recent past. This technological combination is likely to aid in the downsizing of diesel engines in future -- not to boost power, but to maintain power levels while reducing fuel consumption. While it remains possible to downsize diesels and maintain performance/efficiency KPIs, there's no effective end in sight.

In short, Dr Hahn won't go on record saying he sees an end to diesel development, despite the signs that petrol engines still have more development life left in them -- and despite no lesser car company than Mercedes-Benz forecasting the end of diesel development within five years.

"It seems that the [development] steps on the gasoline engines look bigger than on the diesel engines," explains Dr Hahn. "The base [for] the gasoline engines... is lower than diesel has already achieved.

"Unfortunately, there's not only light, there's shadow."

Dr Hahn points to the onset of Euro 6 and future emissions standards that will legislate against particle emissions from petrol engines -- something not previously encountered by the automotive industry. Mazda seems to have overcome this problem to a significant degree with its SKYACTIV technology, but based on what Dr Hahn says, it seems that many car companies are still grappling with this problem.

The doctor also explains that particulate filters for petrol engines may be compelled by market forces, just as happened with filters for diesel engines.

"In the European market there have been technical solutions for internal combustion optimisation... for diesel engines that need particulate filters for Euro 4. But the mood changed; the acceptance of the customers changed. One [company] came up with a diesel particulate filter -- and then everything changed rapidly. All the others were more or less forced to introduce a particulate filter, because it became a sign of clean engines.

"We see ourselves eventually [confronted] by the same engine with gasoline engines.

Kia is interested in Benz's work with DiesOtto, although the Korean company refers to it as CAI -- Controlled Auto Ignition. For the time being, according to Dr Hahn, it's very much a laboratory test subject, rather than a series production prospect. 

What's the go with Stop-start?
One already well-established way for petrol engines to approach the efficiency of diesels is the automatic stop/start facility that cuts the engine when the car is not moving. Without the engine idling, fuel isn't consumed, of course. In some ways, it's technology that lends itself a little better to petrol engines than diesels.

But in a recent economy car comparison conducted by the Carsales Network, this feature didn't perform to expectations. Does it work in practice, we asked Dr Hahn, or is it a kludge that helps car companies achieve respectable figures in NEDC testing -- the standard for European vehicle fuel consumption?

"In the real world, and especially if you use it very often in the urban cycle, it is a real, excellent measure to reduce real-world fuel consumption," Dr Hahn replied. "That's what we get back from the customer, but also what we tested -- not only in the NEDC, but also in the real-world usage.

"Typically, NEDC is defined [as starting from] a temperature of 20 degrees -- so with a cold engine. The start-stop doesn't work for the first [test], because there is a kind of ranking in the electronic [program] for start-stop that means safety is number one. If there is any reason for the engine management to assume that stopping the engine could be a safety problem, then of course it does not stop. If the charging level of the battery is too low, it does not stop.

"If the outside temperature is too low and you have to de-ice your windshield, it does not stop. If [there is] some electrical consumption, like your heated rear window, it does not stop.

"On the next level after safety there comes comfort. That is one reason the start-stop system is only activated as soon as a certain coolant temperature is achieved. That is the reason it does not work from the very first start and stop in the NEDC.

"It is not a cycle-beating measure, it is a real-world measure."

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