I did see some info. about that...I have a plastic tank in my Superduty...no worries. Lots of anecdotal evidence floating around. Ron - are you forced to use B15 if you don't like it? I'll end up using the rest of the tank as an additive to cut the petro stuff. Once it's down low enough I'm filling it up with petro to make it a 20% blend. Zab - thanks for the info.. Any suggestions on what to treat this stuff with?