Let me add some more confusion. I think the law is clear that only a "use class" vehicle has to pay the extra tax. What is confusing is what exactly is a use class vehicle.
This first definition is the current AZ law taken from their official website:
"Use class motor vehicle" means a motor vehicle that uses use fuel on a highway in this state and that is a road tractor, truck tractor, truck or passenger carrying vehicle having a declared gross vehicle weight of more than twenty-six thousand pounds or having more than two axles."
This is a definition of Use Class vehicle in Az that I found on a document that was dated in 1998. Whether they are quoting from the actual statute at the time or not I don't know:
"Use class vehicles include a road tractor, a truck tractor, a truck, having a declared gross vehicle weight of more than 26,000 pounds or having more than two axles or a passenger carrying motor vehicle designed to seat more than 20 occupants."
So as we can see, assuming this is an actual quote of the law from 1998, RV's would not be included as a use class vehicle back then. So the question is why did they change the wording of the law and what is intended by it? Based on the older law referring to the 20 occupants, I'm under the impression that in fact "Passenger Carry Vehicle" is intended to mean a vehicle carrying passengers for hire or for commercial purposes. If that is the case, then I don't think the use tax law applies to motorhomes at all, even if you have three axles.
