mhotujecmhotujec Member Posts: 3
edited March 2014 in Volkswagen
I am very intrigued by the possibility of running a vehicle on renewable resources that come from our own country. I know that on VW's new TDI engines, they won't allow biodiesel without voiding the warranty.

I'm looking for suggestions on older diesel powered vehicles that are already out of warranty and, more importantly, are cheap so I can play around with biodiesel.

Unfortunately, Edmunds vehicle search page only asks about the number of cylinders and not the type of engine. Not having paid too much attention to diesels before reading a lot about biodiesel in the last few days, I don't know where to begin looking.

Any suggestions?



  • mullins87mullins87 Member Posts: 959
    Are you wanting a car, compact pickup or a full size truck?
  • swschradswschrad Member Posts: 2,171
    they spent a lot of time and energy working out home ethanol and biodiesel stuff in the 1970s, running demo cars all over the place for lobbying purposes.
  • mhotujecmhotujec Member Posts: 3
    I'm not looking for any particular type of vehicle. I'm looking for a vehicle with a diesel engine that is known to be reliable and old enough to be fairly cheap.
  • fowvayfowvay Member Posts: 29
    Biodiesel will run in any diesel engine. As for VW voiding warranties in the USA, this is because they have not tested the type of biodiesel that is available in North America on their products and therefore won't warrant the use of a unknown product. Biodiesel in the USA is not regulated to the point that ensures a quality product in all areas.

    In North America you will see soybean based biodiesel and WVO (waste vegetable oil) based biodiesel. In Europe the biodiesel mainly comes from rapeseed and is a slightly different complex from soy based diesel.

    The only real concern that you should encounter when using biodiesel on older vehicles is the incompatibility of the highly aggressive solvent tendency of the biodiesel with the rubber and gaskets in the injection system. Biodiesel has the tendency to deteriorate the rubber that is found on older vehicles. Volkswagen says that no modifications are required to run biodiesel on their cars that were built after the 1996 model year.

    Biodiesel has less energy than petrol diesel so you will notice a drop in fuel efficiency but it is well worth it to reap much lower exhaust emissions. Biodiesel contains no sulfur and therefore drops the exhaust emission up to 30% in all measured categories. It also provides a much greater level of pump lubrication than is found with petrol diesel. The use of a lean biodiesel mix of B-2 is enough to double the lubrication parameters of normal #2 diesel. A B-20 mix is normally the recommended dosage for the maximum ecological benefits. If you choose to make your own WVO then B-100 will offer all of the ecological benefits for approximately $.40 per gallon. Just make certain that you keep the water out of the blend because this will cause pump failure. Don't plan on using B-100 when the temperatures drop much below 40ºF either. The cold flow properties are horrible and normal diesel anti-gel additives have no affect on the chemistry of bio-D.
  • mullins87mullins87 Member Posts: 959
    I'd suggest looking for an older full size truck. There are lots of them out there, many with good engines but less than perfect bodies. If you don't mind what it looks like, then an older 3/4 or 1 ton is the way to go. The Ford's and Dodge's by far have the best track record, while GM's track record was not the greatest. However, in my neck of the woods, you can get a GM diesel for about half what a comparable Ford or Dodge will cost you.

    Example: A '96 Chevy C-2500, regular cab, long bed, 2wd, auto, I believe a Silverado, with 110k miles - $7,995. A '95 Ford F-250, super cab, long bed, 2wd, 5-speed, XL, with 125k miles - $15,995. Now, I know there are a few differences in these two trucks, mainly the extended cab on the Ford, but that in itself is not the difference in asking price. Both of these examples are from about 2 years ago and both were on dealers lots.

    Take your time and do a thorough search and be ready to show the money when the right truck comes along, you'll get a good deal if you're patient.
  • sirradsirrad Member Posts: 7
    My business partner has been running his 98 Golf diesel using his own bio-diesel produced with McDonald's used cooking oil for the past 8 months. Car is running fine, although he had some experimentation in the beginning to finetune his bio-diesel process. The obvious was that his exhaust smelled like french fries. He also encountered some diesel freezing problems during the middle of winter.
  • fowvayfowvay Member Posts: 29
    The type of vehicle you are looking for should be determined by how you intend to use the machine. If you are looking for a commuter vehicle to simply drive to work and do some 'around town' driving then I'd look for a older Mercedes Benz or Volkswagen. You can get between 35 mpg and 50 mpg with these diesel powered vehicles so they are very frugal with fuel. There are a few Asian diesels but they are very rare.

    If you need a vehicle for work then the pickup truck vehicle would be more applicable. The fuel economy is nowhere near as good as the automobiles but they do offer utility.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    The problem with "older" diesels is that most of them are pretty rough and ready compared to modern diesels.

    I don't know how far back you want to go when you say "older", but VW diesels from the 80s, Peugeots, and American diesel trucks are nasty things to drive.

    The 80s Mercedes turbo-diesel would be a good choice if by "old" you mean really "old"--probably the only choice for a diesel that is tolerable to drive by modern standards. And they are pretty cheap, too. Of course, you'll have to wade through 50 junkers to find a good one.

    Figure 25 mpg average.
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