Ok here is my 2¢….
The stuff is good for the engine and environment.
It is really cheaper to make than everyone says (meaning Willie and his group and the oil companies). It can be made out of any veggie oil out there and also a number of oil crops that are easy to grow. The downside is that there are a few chemicals that are used to convert the oil to biodiesel, mainly alcohol and lye.
The sad thing is that many people think that they can go and get veggie oil and just put into their tank and go. There are too many things that need to be removed in order to make it a useable vehicle fuel. I just read one article that says get some waste oil, like french fry oil, strain it and put it into your tank. That is a good way to clog you filers and lines up.
Is it better? Yea… it runs cleaner and even provides some lube to the IP that was taken out, i.e. sulfur. Soot is also reduced both in exhaust and in the oil and if you use french fry oil it smells good. The mileage is a bit less because the BTU content per gallon is lower than straight diesel, but going from 2.39 to 1.10 a gallon; who really cares.
The funny thing is that it has been around for a long, long time and that the auto companies and a few engine manufactures have tested it a lot and found that there really isn’t much of a problem with it. The only real major issue is the freeze point is much higher than diesel, hence the need to blend for low temps.
I know of one person with a VW who runs their car exclusively on biodiesel (no blend) that her husband makes. Her oil is rather really clean and she has doubled or tripled the oil change miles. She easily puts on 100K a year and has yet had any problems.
I have made it and my cost when all said and done was around $1.10/gal. This included the transportation to pick up the waste oil I used to make the bio-diesel. I could have cut cost even more, but it was an experiment for me at the time and I only made 300 or 400 gallons. I have not purchase it from anyone simply because I don’t want to pay $2.00/gallon.
I have run it straight, blended 80/20, 70/30 and 50/50 with no real difference in performance. My truck did smell like french fries.
The thing that gets me is that I used off the shelf products to make it with no quantity discount and it came out at $1.10 a gallon, but a refiner or producer could make it for 30¢ a gallon or even 15¢ a gallon with quantity discounts for the materials used.
I don’t make biodiesel anymore, sold everything to pay the bills a while ago and parked my pickup. It didn’t cost much; I think I had less than $200 invested in everything I needed. The amazing thing is that there are people out there that convert hot water heaters into biodiesel processors.