Bio diesel is known to attack some fuel lines and gasket materials, especially in older equipment. Your 2004 Jetta shouldn't have that problem, so if that's the one that had the problem, it is not the bio diesel. The 01 F250 I believe is also OK but I'm not 100% sure on that one. No idea on the other two.. I like how my diesel engine runs on B100...
dj
dj
