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Wednesday, February 15, 2006

The Next Prius?

Peugeot and other automakers are combining diesels and hybrids -- and raising the efficiency bar.

By Peter Fairley
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Japanese automakers Toyota and Honda Motor launched the hybrid revolution in the 1990s, and their U.S. counterparts are busy following suit. European automakers, however, initially resisted the trend, instead focusing on diesel-powered automobiles whose fuel efficiency rivaled even the best gasoline hybrids.

Now, though, amid rising gas and diesel prices and anxiety over an emerging technology gap with international competitors, European automakers suddenly look set to join the hybrid trend -- by combining hybrid technologies with efficient diesel engines, whose air compression and fuel combustion cycles are fundamentally more efficient than the spark-plug cycles in gasoline engines.

Paris-based PSA Peugeot Citroën last month became the first manufacturer to seize the opportunity, promising diesel hybrids in its showrooms starting in 2010. Although PSA declined an interview with Technology Review, last month its CEO, Jean-Martin Folz, predicted in Paris that the diesel hybrid would provide "a true technological rupture."

PSA is well positioned to tackle diesel hybrid technology. It's the top manufacturer of advanced "common rail direct injection" diesel engines, which feed fuel through engine valves at high pressure and thereby increase combustion efficiency. The company also produces electric vehicles. And this winter it is touring hybrid versions of its popular Peugeot 307 and Citroën C4 compact diesel cars on the auto-show circuit.

The nonhybrid 307 and C4, built on a common platform, are already among the cleanest and greenest vehicles in their class, consuming just 4.8 liters of diesel fuel per 100 kilometers (49 mpg) in mixed driving. The hybrid versions do much better by supplementing the diesel engines with nickel-metal hydride batteries and electric motors akin to those in the Toyota Prius and in Ford's Escape hybrid SUV.

The PSA diesel hybrids start on electric power exclusively, avoiding the use of diesel in low-power, low-temperature modes where the engine is least efficient. During braking, the vehicles recover energy by recharging their battery packs. Fuel consumption falls to just 3.4 liters per 100 km (or 69 mpg), setting a record for a European compact family car, and far surpassing the benchmark Prius (which delivers around 50-55 mpg).

Further distinguishing PSA's diesel hybrids from existing hybrids is a button on the dashboard labeled "ZEV" that enables the driver to put the vehicle into a battery-only, "zero-emissions" mode at speeds up to 50 kilometer per hour. That feature could be handy for drivers navigating the increasing number of European cities that are banning conventional vehicles from their congested downtown streets.

PSA's diesel hybrids are not alone on the auto-show circuit, though. Last year GM demonstrated a diesel hybrid sedan built at its European International Technical Development Center in Russelsheim, Germany. Ford, which co-produces diesel engines with PSA for its European vehicles, has been testing a diesel hybrid van in the U.K., and unveiled a sporty diesel hybrid at this winter's auto shows. PSA, however, is the only maker committed to actually producing a diesel hybrid vehicle.

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  • The next Prius
    Guest (dk5ate) on 02/15/2006 at 12:00 AM
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    Seems a bit crazy to add the cost of a diesel to the already expensive hybrid. Why not just diesels. The hybrid seems misplaced whether gas, diesel or fuel cell. Just keep improving the IC engine and move to hydrogen when nuclear and renewable become more commonplace.
    Rate this comment: 12345
  • Peugeot's ZEV button
    Guest (Felix Kramer) on 02/15/2006 at 12:00 AM
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    "utton on the dashboard labeled "ZEV" that enables the driver to put the vehicle into a battery-only, "zero-emissions" mode at speeds up to 50 kilometer per hour."

    That sounds a bit like the EV button in Prius (about 1 mile electric range) that inspired us (CalCars.org) to build PRIUS+. Or maybe it's like DaimlerChrysler's Sprinter van plug-in hybrid prototypes (20 mile range). Can anyone point to specs on the battery's capacity and range?
    Rate this comment: 12345
    • Why not hydrogen combustion engine?
      Guest (Gabe) on 02/15/2006 at 12:00 AM
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      Hydrogen could be used as a regular fuel in internal combustion engines. No expensive fuel cell or hybrid technology needed. Yes, the range of the hydrogen powered vehicles would be shorter. Nevertheless, most people have short commutes - no need for a 500 mile range.
      The hydrogen could be produced from nuclear power, hence the entire energy chain would be clean. No dirty oil involved (politically and environmentally), no carbon emissions either. And disposing of the radioactive waste is an overblown problem - in fact there is no problem. The writing is on the wall, people just have to see it.
      Rate this comment: 12345
      • Being discussed
        Guest (David) on 02/15/2006 at 12:00 AM
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        There's been some discussion of hydrogen combustion with boron hydride derivative as a fuel carrier.  In many ways, the chemistry/technology is not new.  But making sure it's safe is still an issue.  I'd prefer the combustion engine to fuel cell/electric at this point.
        Rate this comment: 12345
      • RE:  Why not hydrogen combustion engine?
        Guest (Larry Rose) on 03/01/2006 at 12:00 AM
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        Gabe,
        the Fuel cell foccus stores 4 kg of usable hydrogen,  that is very close to the energy in 4 US gal of gasoline.  If that same tank were used in a std Foccus convereted to run on H2, without hybrid built in,  your range in an H2 ICE Foccus would be about 88-140 miles (22-35 mpg),  depending on how you drive and transmission choice.  Also,  a Kg of H2 retails right now for $3.00
        Rate this comment: 12345
    • ZEV range
      Guest (Peter Fairley) on 02/15/2006 at 12:00 AM
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      According to PSA their diesel hybrids have a 5km range in ZEV mode. The battery is a 6.5Ah NiMH battery, which I believe is similar to what the Prius carries.
      Rate this comment: 12345
  • We need these compact diesel-electric hybrids in the USA!
    Guest (Renewable Electricity Solutions) on 02/15/2006 at 12:00 AM
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    These French PSA Peugeot Citroën cars are excellent! I want their hybrid compact car with the '3.4 liters per 100 km (or 69 mpg)' fuel economy which has a ' 'zero-emissions' mode at speeds up to 50 kilometer per hour' (34.5 miles/h)! It is also great that this French company makes battery electric cars, but they need to import those cars to the USA!
    Rate this comment: 12345
    • Re: We need these compact diesel-electric hybrids in the USA!
      GreenCar on 05/09/2007 at 3:53 PM
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      I have been interested in Citroen and Peugeot vehicles for some time.  Even their non hybrid small and midsized Diesel powered vehicles get great fuel mileage, typically 30-40+ city/ 50-60+ highway.  Though they are not currently sold in the US, my communications with them have discovered US sales are still an option.  The best way to persuade PSA Peugeot Citroen to bring these cars into the US is to contact them and provide hits on their web site.  View their web address at http://www.citroen.com/CWW/en-US/RANGE/PrivateCars/C4_5p/default/08112005_MOTORISATION.htm  The en-US in the address appears to be English language USA, so its critical to hit this address for them to count US hits.  I have not seen a US Peugeot web site.  The Citroen web site shows fuel mileage figures of 39/58.6 mpg for the C4, a mid size Citroen.  (To calculate US MPG divide 234.36 by the l/100Km listed.)  For those not familiar with European terminology they measure fuel consumption in liters consumed per 100 Kilometers driven.  Urban is city driving, Extra-urban is highway, and combined is mixed driving.  For even better efficiency check out the C3, C2, and C1.  The C1 diesel gets 69MPG Highway.  How about a C1 Hybrid?
      Rate this comment: 12345
  • speaking of hydrogen cars...
    Guest (Gabe) on 02/15/2006 at 12:00 AM
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    Mazda is already making a car suitable for hydrogen combustion. Paste this link into your browser:
    http://www.cnn.com/2006/AUTOS/02/15/mazda_hydrogen_car.reut/index.html
    Rate this comment: 12345
  • Diesel Hybrids
    Guest (Priusmaniac) on 02/16/2006 at 12:00 AM
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    This diesel trend is just going the wrong way. It makes the thermal engine part of an hybrid vehicle larger, heavier and more costly; while exactly the opposite is sought. A small, light and cheap engine. Something that leaves spare mass, volume and money for more powerfull motors and batteries.
    Rate this comment: 12345
  • Would a small turbine engine be more efficient then ICE?
    Guest (bill) on 03/01/2006 at 12:00 AM
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    Always curious about this.  It seems like a small turbine engine would be more efficient than an ICE for the power generation component of a hybrid system.  Any thoughts?
    Rate this comment: 12345
    • RE:  Small turbine
      Guest (Larry Rose) on 03/01/2006 at 12:00 AM
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      Altho a turbine is ideal for electrical generation,  they are limited by Carno efficency  to about 30% for a simple cycle. a TDI ICE has a peak efficency of about 42%. If a bottoming cycle were used (like in powerplants) to make use of the HOT exhaust, They could be as efficenbt as a fuel cell,  and burn dam near anything,  because they run so hot.  NOx emmisions could be a problem,  as combustion tempratures are driven higher for better efficency.
      Rate this comment: 12345
      • re small turbines
        Guest (swchristensen) on 05/12/2006 at 12:00 AM
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        1
        what about using then ethynol?
        Rate this comment: 12345
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