[instarx]

Algae-based biodiesel is here? That's a surprise to me and I'm pretty tuned into the biodiesel community, since I only use B100 in my diesel truck. Show me some. Or even show me a link to a production site that's anything other than a lab experiment or proof of concept. I can probably make biodiesel out of my cat's poop, but that doesn't mean it's here as a fuel.

I'm sorry to be so contrary, but a lot of the things you say about diesel and biodiesel is subtly incorrect. It isn't that manufacturers won't warranty an engine running more than B5, its that they will only approve fuel for use in their vehicles that is below B5. That's not quite the same thing. Because their diesel vehicles are certified to meet air pollution limits using #2 diesel, not biodiesel, they cannot say it's ok to use high concentrations of biodiesel even when their engines may run fine on it. If they did that they would get into huge trouble with the EPA for approving a fuel that might put their fleet out of compliance. However, if the owner decides to use ASTM-certified B100 the manufacturer cannot deny his warranty because he did.

There is also the problem that some jokers will call anything biodiesel even though real biodiesel is only created through the esterfication of biological fats or oils. I'm sure the manufacturers don't want to open up the rat's nest of a bunch of poor slobs putting god knows what into their tanks and destroying their $25,000 engines because someone told them it was biodiesel. Diesel engines are so robust they will handle 5% of almost anything except gasoline and water (and maybe even gasoline). They might very well deny warranties in that case, and rightly so.