I've often wondered if the way the rule was written...if your car is registered for the street are you exempt from the fuel testing requirements or is the owner's manual an additional requirement?

It's never been clear to me if cars meeting #3 are required to follow #2 or exempt from it.

Also not clear whether a car that is licenced for the street but has had emissions controls devices removed falls. Doesn't meet #2. Meets #3.

2. Those vehicles which have emission control devices
removed and which are not registered and licensed for
street operation may use any gasoline meeting the requirements
of GCR Section 9.3 Fuel.
3. Those vehicles registered and licensed for street use shall
use the fuel specified by the workshop/owner’s manual.