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  1. #11

    Hybrids versus biodiesel; who's cleaner?

    ULSD diesel is available in many places in California and the Pacific northwest, as well as a few locations on the east coast- it will be available everywhere in the US by 2006. Using ULSD will improve the pollution somewhat in the average diesel car or truck, but for big improvements, they will have to specificly design new catalysts and particle traps for future car models (they will not be retrofitted except for fleets and municipal busses). The sulfur poisons these advanced catalytic converters.

    In Europe right now they have ultra low sulfur diesel at 50ppm (the US is aiming for 50-15ppm gradual phase in). All the new Volkswagens have the particle traps and catalysts. They slowly oxidize the particulates while you drive, and occassionally use an afterburner to purge the filters. You can't get those in the US, though all the VW's in the US have emission controls in them, such as exhaust gas recirculators and catalytic converters.

    In the 70's, they didn't come out with unleaded because they wanted to get rid of lead (airplanes still use leaded gasoline). They came out with unleaded gas because the lead was poisoning the catalytic converters in gas cars (BTW, Honda's cars didn't even need catalytic converters for many years, because they were so efficient). The lead added to gas was actually added as an octane booster. Now they use ethanol or MTBE.

    A diesel engine such as the TDI in a US late model Jetta or New Beetle emits about only 90-95 percent of the pollution than a diesel did 20 years ago. Diesel cars aren't smoke belching monsters anymore. Traditional pollutantion in auto exhaust has basicly been solved and any further emission reductions will be very costly with diminishing returns. OTOH, CO2 emissions from vehicle are probably as high or higher than they were 20 years ago. Europe has tended to favor fuel economy and CO2 reduction over worrying about aggressively controlling pollution- they are reducing diesel exhaust pollution, but they also are working with the industry in something more than an adversarial role, which is something that cannot be said for the EPA and CARB in California. As a result, Europe is on schedule to meet their Kyoto treaty obligations. The US hasn't even signed the Kyoto treaty.

    The big danger is that diesel technology will not be able to meet the 2007 and 2009 EPA and carb goals. Meeting CARB's limits on diesel pollution will require an engine that emits 95 percent less pollutants than a diesel of today. I just don't see how that's possible without seriously compromising fuel economy or performance. The EPA and CARB may well have to moderate their stance, or they will end up with diesel being nonviable. And that will cause serious economic harm to the whole country (since most everything you buy in stores comes via diesel, gasoline engines just are not an acceptabe substitute).

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  3. #12

    Hybrids versus biodiesel; who's cleaner?

    Just a note on CO2 production, biodiesel effectively produces zero CO2 when viewed from a lifecycle standpoint. If you want to get very high level, biodiesel is basically liquid solar power. It's mainly made from plants which by photosynthesis and CO2 consumption grow into something that can be harvested to produce biodiesel. From that standpoint, the only fuel that can compete with biodiesel is Ethanol, which is generally less cost effective than biodiesel.

    I'm not worried that they'll be able to meet the new guidelines. Stuff shipped by truck generally means fleet vehicles that cost anywhere from $40k for a small, short-hop delivery truck to $500,000 for a long haul truck. The fuels can be cleaned up enough to make emissions controls possible without things like sulpher poisening and clogging the emissions controls. Then even if you spend $5000 for an industrial catalytic converter on a semi, it's a one-time, 1% addition to the cost of the vehicle in exchange for radically reducing it's polution output. That's worth spending money for.

  4. #13

    Hybrids versus biodiesel; who's cleaner?

    But add the costs of these catalytic converters to cars and you might have a car priced out of the market. There is debate as to wheather it is even achievable with diesel engines, which is why GM, Ford, Toyota, etc. have been playing it very conservatively with diesel in the US. Only VW has stayed in the diesel car market, and it's been a rocky last few years, with only the smaller cars having a steady presence as emission standards tighten, yet fuel standards don't improve (perhaps Volkswagen should sue somebody- the refiners or the government, for lost profits).

    Soot is a byproduct of internal combustion engines. Gasoline engines of course emit less, but where is it going to end? The fact is that diesel exhaust was declared a Class-A carcinogen by a highly biased panel of experts based on only a few studies- ignoring studies that didn't show any correlation at all (eg., a study of NY firefighters finding no correlation to years spent working around diesel vehicles vs. cancer rate). Is it going to be like second hand smoke; no official "safe" limit? You are going to have to put alot more emissions controls on vehicles to make them "clean" enough to appease people who believe that environmental factors are a significant cancer threat (and they aren't- the biggest cause of cancer is genetics, followed by diet and lifestyle).

  5. #14

    Hybrids versus biodiesel; who's cleaner?

    I'm in the same position. I've concluded that biodiesel is 'cleaner' and 'better'.

    Hybrids still use fossil fuel. That means fuel that has been transported a long way already, at enormous social and environmental cost.

    A very efficient diesel gets better mpg than a hybrid, with fuel that is produced more locally, that is renewable, and that adds no extra carbon dioxide to the atmosphere.

    I'm going to have to make my own biodiesel which is a hassle. If you can get it nearby, so much the better.

  6. #15

    Hybrids versus biodiesel; who's cleaner?

    The difficulty is in the definition of 'cleaner'.

    I actually am using both - I have a diesel van (Toyota Coaster as a camper) and I'm lucky enough to live near a retail outlet with Biodiesel. I also have a Prius.

    The ideal would obviously be a diesel hybrid, but I understand that some european manufacturers have been trying and found it much harder with diesel than gasoline.

    The emissions from a biodiesel vehicle will be mostly CO2 as the fuel itself is reasonably clean. There should be little soot and other nasties. It should be noted that Biodiesel is not a single standard fuel but will vary by crop, location, season, style of processing and other factors. The use of second hand oil introduces an unknown and variable list of additional chemicals.

    There are perhaps significant differences in the application that should be considered.
    My Prius is excellent for commuter travel - the hybrid excells in stop-start conditions and the hills where we are.
    The diesel Coaster we tend to use for longer trips 100's to 1000's km and it just loves to cruise for hours - where the hybrid is really just extra weight.

    So until a diesel hybrid is available perhaps the question should be what kind of driving are you doing? Stop/start pick the hybrid - cruising go for diesel.

  7. #16

    Hybrids versus biodiesel; who's cleaner?

    One problem. The most common form of biodiesel is B20. That's only 20 percent biofuel, and 80 percent petroleum diesel.

    In order to run more than 20 percent biofuel you have to modify the vehicle with such things as tank heaters to keep your fuel from congealing on you.

  8. #17

    Hybrids versus biodiesel; who's cleaner?

    I would say that biodiesel would be better. Yours desil will problibly last you most of your life. Another thing is that if you buy a desil and use biodesil you can buy a kit to convert it to pure vegtable oil. The car starts and shuts off on desil or biodesil and then runs on pure vagtable oil. VEgtable oil is cleaner thatn desil or biodesil. Yoy may ask why would i do this 1 Litre of vegtable oil costs you $6-7 canadian? But i am sure all or most know a resteraunt that uses vegtable oil and they may give it away to you because they usally have to pay a throw out fee. So you would be helping them. There are so many fast food resteraunts or anyresteraunt that makes deepfried food like fries. Mcdondalds,BK ,wendies, DQ,A&W,7-11, and so many more. Also you could grow vegtable oil. If you have a garden like i do plant some un-food grade corn the one that feeds cows and make it into vegtable oil. If anyone is interested in this idea
    go to www.greasecar.com

  9. #18

    Hybrids versus biodiesel; who's cleaner?

    If you compared a Jetta Diesel getting 36mpg runnign on bio-Diesel to an Escape Hybrid getting 32 mpg, I think the bio-Diesel wins with a lot less emissions plus on the build side, no battery which is a production/disposal problem.

    Comparing the Jetta Diesel to the Prius, the bio-Diesel comes pretty close to matching the Prius on emissions, again less impact with the bio-Diesel Jetta on production/disposal since no battery make or dispose of in the life cycle.

    Jetta has a top crash rating from Isurance Institute also.

  10. #19

    Hybrids versus biodiesel; who's cleaner?

    you do not have to modify any of the new diesel cars to run b100 (100% biodiesel)
    there are several stations around my area that carry b100. I use it all of the time in my 2004 jetta tdi
    even in the winter the b100 works well.
    plus my MPG for hwy is 50 and i get 40-45 mpg driving around d.c. when im commuting.
    plus the biodiesel is less expensive.

  11. #20

    Hybrids versus biodiesel; who's cleaner?

    Note that biodiesel is typically only a small fraction of the diesel fuel. Yes it's emissions are 10x cleaner but diesel is really realy nasty compared to LPG or even gasoline.

    If you can do it - make your own 100% biodiesel and don't mix in any petrolium products at all. That would give you the cleanest option that is available now esp with the new VWs that get exceptional milage.

    I expect big changes in hybrids as they eventually start to make some that get good milage. The technology is currently new and not suited to low emissions - it's simply lower emissions than our current gas guzzlers.
    You pay thru the nose, you take a gamble and you're not much cleaner.

    You can make much more signif changes thru your lifestyle. Drive less, bicycle to work or use public transit. Read Your Money Or Your Life sometime!

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