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This prototype 1.2 Liter, 3-cylinder turbo diesel is classified as meeting Europe's Tier 4 emissions standards. Used to power the Eco Target Car, which is based on the Opel Signum, is mated to an automated manualtransmission and (10 kW continous, 22 kW peak electric motor. According to the author the diesel is a bit noisy, as are the car's inverters, which he reports will need to be quieted down significantly before being acceptable to the driving public.

Towards Cleaner Engines in Europe

Exclusive report from AVL powertrain conference in Graz, Austria

By Richard Scheffenegger

EV World's Austrian correspondent recently attended the 2004 AVL powertrain conference in Graz, Austria September 9-10, 2004. While the primary focus was on how European automakers and their suppliers can bring internal combustion engines into compliance with tougher CO2 and smog emissions regulations, there was also talk of alternative powertrains. EV World's editor contributed to his report.

Perhaps more than anywhere else in the world, Europe is concerned about the impact of climate change. The deaths of estimated 50,000 people across Europe in the summer of 2003 due to unusually high temperatures, only confirmed many European's worst fears. Long before the Bush Administration admitted the existence of global warming, Europe recognized the role played by carbon dioxide emissions from automobiles and manufacturing and power generation in altering the climate of the planet; and has led the way in calling for Union-wide reductions in CO2 and other greenhouse gas emissions, starting with automobiles. Across the EU, European, Japanese and North American carmakers are being called on to reduce the emissions of their vehicles. The conference in Graz, Austria was convened to discuss strategies and share knowledge.

European automakers have agreed to reduce the average CO2 emissions of their fleets to 140g/km in 2008. Still in discussions are the limits for 2012, with the target being 120g/km. But as several presentations during the conference pointed out, that even with the most optimistic forecasts for technological implements, average global temperate during the 21st century is still expected to rise 2-3 °C One of the major culprits is the rising number of motor vehicles and total miles traveled. One study presented at the conference suggested that even if all the cars in Europe were as efficient as the new Toyota Prius, which produces half the CO2 of conventional cars, it really will not be enough to reduce the total CO2 emissions because of increasing miles being traveled and numbers of new cars being added. In China alone, 14,000 new cars take to the roads every day. Beijing adds 30,000 new cars every week.

While diesel vehicles have been a huge success in many parts of Europe where gasoline costs from $3.50 to over $5.00 a US gallon, hybrids have made only modest inroads, though this is expected to gradually change as carmakers wring out more improvements from the conventional IC engine and drivetrain.

Overall, the conference attendees and speakers agreed on the fuel savings of mild hybrids to account for 5 to 15%. However, most also indicated, that the further development, and exploration of new internal combustion engine technologies will very likely also lead to fuel savings in the same order of magnitude. It is my impression from the conference that most manufacturers more likely will first follow a cautious, incremential development path that includes down-sized, turbo-charged engines mated to improved transmissions like consumption-oriented, automated step-transmissions, before adding the more or less mild hybrid option.

However, it was also indictated, as expected, that some fuel economy improvements will be accompanied by disadvantages regarding other emissions (most prominently NOx), or that the fuel savings due to better engines, will be eaten up by more complex after treatment systems - especially for diesels, which are very popular here in Europe.

In some configurations, diesel engine hybridization may already offer the promise of reaching tougher forthcoming US and EU diesel emission rules. However, there is likely to appear a trade-off between a cleaner diesel exhaust and higher fuel consumption. The reason is particulate filters, which are popular in Germany, increase fuel consumption due the need for higher exhaust temperatures from time to time, and higher back-pressure.

Even in a mild hybrid drivetrain, this increased power output of the engine could be temporaily stored and used to boost driving power later on, thus decreasing the overall systems CO2 emissions again. Some manufacturers now artificially put more load on the diesel engine in order to heat up the exhaust gas temperature by turning on the window defoggers, A/C compressor, even without driver demand. Others inject fuel directly before the particulate filter.

Of particular interest to me was the new Ford Escape Hybrid. I talked to Scott Staley, who is second in charge of the Escape Hybrid program, about the hybrid in general and its battery management system, in particular. Originally, Mary Ann Wright was to attend the conference also, but as head of the project, she was unavailable this week.

According to Staley, Ford uses an active thermal management system or the battery in the Ford Escape Hybrid, which uses Sanyo NiMH D cells, consisting of a seperate coolant loop from the very first radiator to the pack in the rear. The coolant can even be heated by electric heaters for freezing conditions.

Disappointingly, there are currently no plans to introduce the Escape Hybrid in Europe, at least with this model generation. Staley explained that despite significant pre-orders for the first American-built SUV, production capacity is still fixed at 20 000 units per year. Depending on the success and real-world expirience with the Escape Hybrid, Ford might re-evaluate the vehicle, and potentially export it to other markets. They seem to be following the same strategy Toyota used when it introduced the first Prius in Japan in 1997, i.e. keep the vehicles sold to customers close to their labs and facilities. This is, no doubt, a smart move because the Escape Hybrid is definitely more complex than anything Ford has built to date; and it has no real-world experience on customer usage and wear patterns. However, with we should expect that when the next generation is rolled out, Ford will re-evaluated potential markets.

So, for the time being at least, Ford wants to keep the vehicle relatively close to home so it can monitor vehicle's performance in consumer hands. Of particular concern is the thermal management system that contols the electric/hybrid components. This will be watched closely, especially because all the tubing adds a lot of complexity and safety issues. Depending on what Ford learns, it is likely to look for ways to remove or at least lift the strict thermal control of the battery in the next generation.

Next, I met up with Mr. Killmann, director of powertrain engineering of Toyota Europe. During the course of the conference, he was repeatedly asked about the cost and profitability of the Prius. According to his explanations, Toyota was able to cut production costs of the hybrid parts of the drivetrain, definitely including battery, inverter, motors, transmission and probably the electronics, wiring and auxiliary components, by about 70%. However, he didn't indicate precicely if this figure was compared to the Prius I NHW10 (Japan version) or Prius I NHW11 (international version).

I also learned that between 2000 and 2003, Toyota sold about 4500 Prius across Europe. Of all these, only about 35 batteries have been returned to the company, most from wrecked cars, a few from inpropriate replacements (i.e. replacment of a non-defective battery), and only a very small number for studies by the battery manufacturer. None have been replaced so far in Europe for any real issue. I estimate that about 100 of these Prius have been bought through various channels by all the local manufacturers, universities and R&D institues to study the layout, or to get to high-quality NiMH batteries to power prototype cars like the VW Bora Hybrid and the Zytek Hybrid Smart.

Equally interesting, the warranty costs of the Prius hybrid transmission were said to be lower than the warranty costs of manual transmissions in other Toyota models, with the guarantee costs of ordinary automatic gears being even higher. The original engineering target was a reliability between that of a manual and an torque-converter automatic transmission - although toyota didn't give an indication, what the exact numbers were.

Toyota also made it very clear that the electric motors were certified under all engineering target scenarios with regards to the oil pump (which is operated by the ICE shaft). Thus, I assume, that even the use of the EV mode directly after an extended stand-still period was certified, and the bearings do receive enough lubricant with only the electric motors spinning.

Everyone at the conference acknowledged the Prius as the de-facto baseline standard for a full-hybrid car. For its part, Toyota admitted that the Prius is an extreme in regards of fuel savings and low emissions, and that now the company will focus more on high-profitable SUVs and power / sports cars, to make a higher profit on hybrids.

Times Article Viewed: 4873
Published: 08-Oct-2004

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