i've heard somthing like, for every % of bio you use you get that many cents off per gallon as tax credit. example b20 would be a 20cent credit for every gallon of b20 you bought that calander year and b99 would be a 99cent credit, etc. Not sure if its true, and haven't really looked into it but got that impression from some people i talked too. Has anyone else heard this? I don't want to spread a rumor. As of now I try to keep all my reciepts when i buy BIO just in case.