Check out www.biodiesel.org
, which is a good place to start. It has a retailers map so you can see if anyone retails it in your area. (this is great when you travel with it!) There are 3 stations within 30 miles of our house, but only one is convenient by DH's office. So he just is aware of making sure he fills it once per week when he leaves work on Friday. The nice thing about biodiesel is you can store gas cans in the trunk or garage (we have 5 gallons in each, which is quite a lot of miles on that small car) as an emergency if you can't get to a biodiesel retailer for some reason. Of course, if you're really, really frugal (grin) you could make it in your garage.....I'm sure our neighborhood CCR's say something against that!!
A web search for biodiesel will get you a bunch of other sites also. Green Car Co www.greencarco.com
is in our area, but they are a really nice family owned business, and I'm sure if you called them up, they would have some great resources for you and / or discuss TDIs and such. There's probably a bunch of links on their site too.
You may want to consider whether you're buying a Jetta TDI new or used. The VW dealer by us said the warranty is void in the US if you use bio-diesel. We bought ours in 2005, and it's a 2002, so the warranty was pretty much over, so that wasn't an issue for us. I know people who buy new and don't tell the dealer when doing warranty work, but....I don't think I could do that.
We get 45 mpg average, with a bit of city driving and mostly freeway 70-75 mph driving. The freeway by us is 70, so maybe we'd get better mileage if we were driving 60 instead(?).
We _love_ our Jetta. Love it! It's definitely not our family car (I have a 98Toyota Sienna for DD and the furry kids, and it will probably last forever, but we'll replace it with some kind of diesel when it's done.), but DH uses the Jetta to commute and we both use it anytime it's just one of us in the car. It's zippy and I feel safe in it, despite SUVs / Hummers / everything being huge around here.
The only repairs we've had to do in a year+ of a lot of driving is that when we first got it, we had to replace the fuel filter (I think?? DH isn't here to confirm that it was the fuel filter) twice so that it would transition from petro-diesel to bio-diesel. Something about it you don't do that, the two fuels will gunk up together. (Obviously, I just drive my cars vs. repair, right!) It cost us about $75, and we did it immediately upon buying the car and using biodiesel and then about six weeks later. I'm sure someone who knew how to do it could buy the part and replace it themselves for much less.
Hope this helps! It's so fun to drive the Jetta and talk to "strangers who become friends" when they see you're running your car on bio-diesel like they are. Bumper stickers and window decals abound in our area on diesels, all proudly proclaiming Bio-Diesel! Love it, and what a great gift to yourself and future generations.....can't wait until we have two cars on bio-diesel instead of just one!
Happy car shopping,