This is a cool discussion- unfortunately I didn't see the aforementioned epsode of mythbusters. I have always been a proponent of biological diesel fuel.
About gasoline- try living in Wickenburg, Arizona. In Maricopa county (and I think Yavipi as well) we are "blessed" with special blends of fuel. The price i think was $3.15 at the cheapest station in town for 87. I'm glad I don't have a long way to drive to work and school right now. Even still, the actual difference between operating your car now as opposed to 3 years ago isn't much more then $10 per fill up. It hurts, but it's more apparent then real. In Pennsylvania I used to live in a house heated with oil. THAT hurts when the fuel prices go up. When you keep ~2000 gallons of oil though you can play the market a little throughout the winter.
I think the auto industry needs to push clean diesel technology more then it is currently. I think the current perceptions of diesels are:
1) The garbage truck, or semi starting from a stop light. Smoke grandly pouring from the stacks. Even though the majority of this is harmless carbon (might not smell great, might make you sneeze). These vehicles literally stink and spout soot. Most people do not like this (I am one of the exceptions).
2) The 18 wheeler climbing the mountain. Yeah, we've all been stuck behind a semi trying to go up a steep hill. It isn't much fun. The perception that diesels are underpowered is fueled by the likes of the VW Rabbit (the car that Harry Chaipen was killed in), and some of the other imported diesels. In absolute fairness, I doubt that a LUV diesel is much to write home about when it comes to power, although I can't say that from experience.
These perceptions are certainly unfair. I dare you to try and make a new VW TDI put out soot. I'm not sure it's possible. TDI is not perhaps the best example, since the only version available stateside is a mere 1.9 (?) litres. But they epitomize small econemy in diesels while being extremely clean emissions wise.
How about a Chevy Duramax? Having driven one a few weeks ago, it has PLENTY of power, is only slightly louder then a gas engine, and in stock trim produces little odor and little soot.
I believe I remember hearing somebody tell me about a bio diesel conversion for the Duramax chevy. Not sure of a lot of specifics, but it changes something with the fuel filter and lines to make it safe for biodiesel. I think the intended fuel was a kind of rapeseed oil.
Anyway I think it would be cool if automakers switched the focus to clean diesel. Not only do you have the potential for biological (and renewable) fuels, but you have the potential to be more efficient while not forcing everybody in to little dinky cars that nobody really wants.
Oh, 2 links regarding the "diesel weed":
http://www.popularmechanics.com/science ... 88501.html
http://www.biodieseltechnologiesindia.c ... urcas.html
It ain't veggie oil, but it is a biological, renewable diesel fuel that might be a potential alternative energy source.