Former Fiat exec: VW fallout may hurt hybrids

TURIN, Italy -- Full hybrids and plug-in hybrids will suffer most in the aftermath of Volkswagen Group's diesel emissions scandal, says former Fiat engineer Rinaldo Rinolfi, one of Europe's pre-eminent powertrain experts.

Rinolfi, 68, says the move to real-world emissions tests, which has been accelerated by VW's use of a defeat device to deceive testers, will show that plug-in hybrids are not nearly as efficient when on the road compared with the very low carbon dioxide results they attain under Europe's current guidelines.

This is not the first time Rinolfi, who many consider the father of the common-rail diesel, has shared a bold prediction with Automotive News Europe. In 2005, when he was head of Fiat powertrain, Rinolfi said the move to Euro 6 emission standards, which took effect last year, would end the diesel engine's reign as Europe's most popular powertrain. Automotive News Europe Editor Luca Ciferri met with Rinolfi last month here.

Q: In 2005 you predicted that by 2014 gasoline engines would end diesel's reign as Europe's most popular powertrain for new cars. It looks like the change will happen this year. How low will the market share for diesel go?

A: I'm happy to have envisaged the right trajectory a long time ago. And I am not changing my long-term view: Diesel will stabilize at about 40 percent of the European market by 2020.

How has the VW Group's emissions scandal affected diesel demand?

Little to none. Euro 6 rules, which took effect last year, increased the costs of diesels, making them a very difficult commercial proposition for subcompacts and minicars, which are Europe's biggest and third-largest segments, respectively. This was the real reason for the diesel decline. For long drives on the highway, diesel remains the most cost-effective solution. I do not think that the VW scandal had any meaningful effect on the purchasing decision of the average European consumer.

Will there be long-term repercussions from the VW scandal?

The biggest impact -- and not only in Europe -- will be the faster move to real-world driving emissions tests. This will completely change the powertrain mix from what is favored by the current NEDC (New European Driving Cycle) bench-test-only cycle. Over the years, even without defeat devices, every carmaker has found ways to achieve fuel consumption and emissions results that have progressively diverged from the real driving conditions the customer experiences.

Which technology will be most affected by the change? 

First and foremost, plug-in hybrids. Under the current NEDC you test the car twice, once with the hybrid battery connected and then once without. Depending on the strength of the battery, the first cycle can be run without using the internal combustion engine, resulting in zero fuel consumption and emissions. Since the homologation value is the average of the two tests, you basically halve what the internal combustion engine burned and emitted in the second test, resulting in incredibly low values. 

How different are these results from real-world driving? 

It is about 30 percent to 40 percent lower than what customers get. That means the real-world driving cycle will highly reduce the advantages of plug-in hybrids. I assume that, combined with their considerable added cost, will drastically reduce their appeal. 

Is the same true for full hybrids such as the Toyota Prius? 

Yes, but to a lesser extent. A hybrid powertrain has great efficiency in stop-and-go traffic, but has fuel consumption and emission shortcomings during highway driving. The future popularity of hybrids will mainly depend on the weight of stop-and-go driving in the new real-world homologation cycle. 

Will battery electric vehicles finally become the leading green powertrain in Europe? 

I've been waiting for a true breakthrough for the past 25 years, but I've not seen it yet. Since we launched the Fiat Panda Elettra in 1990 with lead-acid batteries, battery efficiency increased roughly threefold with the move to nickel-metal hydride and then to lithium ion. 

To make BEVs mainstream products that are affordable to the masses you need a tenfold to fifteenfold improvement in battery efficiency. I continue to see only incremental improvements.

What about fuel cells? 

On the technical side, I have a positive view. Fuel cells permit zero emissions with no range constraints and their current high costs could decrease considerably once production reaches industrial volumes -- something that batteries already enjoy. 

What is the most cost-effective solution? 

Considering that after displacement downsizing, turbocharging, variable valve control and direct injection there is not much more that can be invented to further improve traditional internal combustion engines, compressed natural gas is an affordable solution. 

CNG slashes CO2 emissions by 20 percent to 25 percent compared with a gasoline engine. The CNG infrastructure is growing in Europe and a small gasoline tank helps overcome any range anxiety.