Biodiesel
 

I filled up with diesel the other day at a gas station I don't normally frequent, and didn't notice until I had put in 10 gallons that it was a 5% - 20% biodiesel blend. I have to say I didn't really notice any difference in power, but the MPG seemed to be a little lower than normal.

Does anyone have experience with biodiesel, or know much about it?

Yes, I'd advise against its use. My opinion only, others may think differently. Be prepared to learn how to change your fuel filter.

http://www1.eere.energy.gov/cleancit...sues_final.pdf

How to Avoid Problems When Using Biodiesel | eHow.com

Wouldn't touch it, primarily due to the lack of specifications and cleanliness standards. It can be all sorts of things. Agree that you should stock up on fuel filters.

Here is the one we found in the bay area.
Looks good to me... I've been using some, it's also $0.30 cheaper than regular diesel
Upgrade to Biodiesel B20 – Propel Fuels

you can safely use up to B20 (20% bio). Yes, it does offer slightly less power, and thus possibly slightly less mpg, but not much. Research the brand you get or ask them about quality, but using will generally keep your engine cleaner... which is why others say to stock up on oil filters. This is only required when switching a high mileage engine (with deposits) to biofuel (which cleans deposits out). If your engine is new-ish, you most likely will not have many buildups and you can keep your engine deposit free using bio blends. Also, most research shows engines longevity is extended by running bio.

Actually, we didn't say to stock up on oil filters, we said to stock up on fuel filters. That is because of the common issue of clogged fuel filters due to poor quality biodiesel.

The real issue with biodiesel is that the spec says how much it bio (5, 10, 20%, etc) but after that, there isn't much in the way of specifications. Different bio diesel blends can have very different characteristics, it is very open.

Properties that typically vary include density, kinematic viscosity, heating value, and cetane number. It all depends on the feedstock, and it will vary from crop to crop and with the same crop, over time, due to weather conditions when the crop was grown.

Yes, it can burn fine. Or it can be a disaster. If you have a trusted source, and haven't had any problems, then you are less likely to have future problems with fuel from the same supplier, as long as they get it from the same source. But the reason BMW says not to use it is because they, you, and the supplier of it, all know very little about what is actually contains, most of the time.

To compare it to lube oil, which is very standardized as to quality, cleanliness, performance specs, etc, it is like saying that you are going to use oil that comes in blue cans, without having labels that specify viscosity, lubricity, performance standards, etc. Might be fine. Might kill your engine. You will know after you have used it for awhile. Is it worth the risk?

Yes, sorry I meant fuel filters. Not sure why oil got stuck in my brain. I do agree with quality, but any legit/licensed manufacturer would provide quality fuel. Not sure about national/local but here in California if a fuel damages an engine it's *intended* for, that producer is liable for the damages. Which is why I would stick with known producers like the Propel brand mentioned on another thread.

We don't have any manufacturers where I live, it is all homebrew. That can't legally be sold, but some co-ops are importing biofuel blends. Since that props up the ethanol, canola, and soybean producers, all of whom would be otherwise producing food crops, there is some debate on the whole topic. I don't have to worry about biodiesel with my vehicle, but I drive further and pay more in selecting fuels, just to avoid supporting the ethanol industry.

Good luck trying to prove your case in court.

My MB service adviser asked me to put my hand up, and swear on something that I hold dear to promise I would never put biodiesel in my CDI. He showed me a similar car in the service department that had the fuel system completely taken apart, with everybody pointing fingers for responsibility of a $3k bill that MB refused to cover under warranty.

As others have said, it isn't worth the risk, especially with the dubious environmental and economic benefits.

Unless BMW has changed their policy, I believe anything over 7% biodiesel is not permitted under BMW warranty terms. Using B20 gives BMW a hook with which to try to deny warranty work if you get a clogged injector or some such failure.