It has it's own section: "Kei Vehicles/Mini-Trucks"
"Many of these vehicles can be imported. They can be titled in Oregon, but cannot get registration because they were not primarily manufactured for U.S. roads or highways."
Perhaps it is still arbitrary, not supported by a specific regulation (but I don't know that). Still, they aren't hiding their unwillingness to register them.
https://www.oregon.gov/odot/DMV/pages/vehicle/vehicletypes.a...
It has it's own section: "Kei Vehicles/Mini-Trucks"
"Many of these vehicles can be imported. They can be titled in Oregon, but cannot get registration because they were not primarily manufactured for U.S. roads or highways."
Perhaps it is still arbitrary, not supported by a specific regulation (but I don't know that). Still, they aren't hiding their unwillingness to register them.