Audi tech chief sees end in sight for internal combustion

The global automotive industry has just about wrung dry the efficiency gains to be made for internal-combustion engine (ICE) development.

All the low-hanging fruit has been plucked, according to Audi's board member for technical development, Hans-Joachim Rothenpieler. Speaking with carsales during last week's Frankfurt motor show, the Audi executive explained that any future advances in combustion technology would be made downstream from the engine's exhaust ports.

"The ICE, no matter whether you talk petrol or diesel, it's reached a level that's close to the ideal," Rothenpieler said.

"In the combustion process you can tweak it for minimal effects, increasing the injection pressure for better vapourisation – things like that.

"It's all optimising close to the 100 per cent ideal line.

"The exhaust system though... here [at the catalytic converter] we still have large development potential stages; we like to say with a chemical plant fitted behind the engine in the exhaust system, you can still ramp it up.

"It's pretty straightforward. I started 34 years ago at the Volkswagen Group, in engine development. The engine was the cost driver... nobody would talk about the exhaust pipe...

"Today you've got the engine, you've got the exhaust system and the cost [of each] is 50:50."

That, of course, prompted the obvious question: at what point will car manufacturers be forced to abandon further development of ICE? Will it be when the R&D cost for the exhaust system is 70 per cent of the total cost of powertrain development? Rothenpieler didn't answer the question directly, but observed that we're already seeing signs of ICE's slow demise.

"For the small cars we're gradually phasing out the diesel – reducing it.

"And of course you reach that price point – at some stage – where the customer simply can't pay for it anymore."

Cost-saving strategies have been implemented in the past for ICE vehicles and those same strategies can also be applied to electric-vehicle (EV) development. In fact, that's already happening, Rothenpieler said. And the reduction in R&D costs will accelerate as EV model lines grow in number.

"Volkswagen Group [companies] are using synergies, and have been doing this for many years. Of course, the platform strategy... the matrix system, [Ferdinand] Piech started the whole thing 30 years ago, and I think we utilised it to the best, really.

"Of couse we will continue that approach also when it comes to electric mobility. We will take the same tack. There are definitely going to be some components that allow for more standardisation... than with the combustion engine."

But hold everything, R&D costs will rise disproportionately in the short term, according to Rothenpieler – because 'hybrids'. And not just hybrids, but also full battery-electric variants based on the same basic architecture as a conventional ICE model. One example of that would be a future R8 sports car with an all-electric variant developed alongside the petrol model.

"When you look at our model strategy in future, there's going to be plenty of cars that have both an ICE [internal-combustion engine] and an electric motor.

"Which means of course, in this transformative phase we will have a higher number of models... that do trigger model-for-model R&D costs."