Back in my trucking days I used common alcohol in my diesel fuel to thin it to prevent gelling. I didn't have heated tanks but I never had a problem in 8 years of running I-80 & 90 from sea to shinning sea.
Now mountinside chain inspection stations were a different story. :-)
So reading about Bio-diesel is encouraging as I can get an extra gallon of fuel after I fry up a couple hundred chicken wings. It's a win, win, situation!! :-)
Burp.. oops excuse me.
Load up on the Pepto-Bismol. ;);)