I have some old peanut oil, I was wondering if anyone knows anything good or bad about useing it for fuel, or mixing in #2.

Sure - just be real careful about peanut allergies! [nonono]

Im with XLR8R run it but filter out the allergies.[laugh]

How old is it?
Don't know about burning it in a blend with #2 but you should avoid rancid oils when making BD. Used oil should be turned into biodiesel as soon as possible, in order to keep it from going rancid and increasing the amount of free fatty acids. Rancid oil produces less biodiesel and may not even react to make it.

Thanks Bill, I didn't think of that. It is old. Some of it is probably 2 years old. I think I wil just dispose of it properly.

If you have enough to make it worth your while you can add some biocide (check autoparts store) to the oil to kill any bacteria. Be sure to do some filtering and you should be able to add up to 20% in your tank. If it gets below 60F cut it with some kerosene or diesel#1(10%-20%). The next alternative is make full blow biodiesel using methanol and lye, but that would be alot of work and research for just a little fuel additive.[duhhh] If your not sure, just pitch it. Next time buy some biostat and add to your used cooking oil when you are finished with it and it will prevent bacteria.[guitar]

Thanks Foamdoc.