After reading this thread, and looking around the web, it looks like most diesel will be B20 withing a year or two. I am wondering, if the State you are passing through mandates B20 at the pump, and you cannot get anything else, how can a manufacturer deny warranty claims? It would be different if you had a choice, but it looks like most states in 2015 are mandating B20. I did learn one thing, carry a spare fuel filter, it is not the B20 itself that clogs them, but all the other junk that has collected in the system prior to you using it, I guess B20 really cleans up the fuel tank and lines.