You could both be right, there are two different types of non-taxed diesel fuel. The one that Dave is using has no road taxes because he is not driving his pressure washer down the freeway. The other is a special agricultural fuel that is even taxed less or has no tax at all.
Fuel tax #1
Agricultural fuel- only farmers can use this fuel. Some special agricultural bill passed long ago. Your not even supposed to be able to get this fuel price if you don’t show and exception card. The fueling places could be in more trouble if caught than the actual person using the fuel.
Fuel tax # 2
Diesel with no road taxes. Anyone who is not using it in and automobile can use this fuel. In my state there is no special permit they just trust you on your own merit.
Yes, they both have red dye and maybe the exact same fuel just depends on what portion of the taxes you pay.
Yes I think everyone is using the #2 program and its perfectly legal and some are just cornfused. Yes cornfused not confused.
Important Reminder: Many who have access to and use these fuels often become greedy and use them in "On Road" vehicles. Be aware, if you are caught doing so the fines are excessive. Make sure you know the guidelines of proper use and the penalty for failure to follow these guidelines correctly.