It could be called a quad or atv. Not a side by side obviously. I can think of an AMA competitive event you could find a class for it. If someone protested the engine displacement there is an age way to find a class depending. I think a motorcycle is 3 or less wheels and less than 1000 pounds, not sure if that is gvwr or curb wt. AMA (American motorcyclist association) has swollen to include the four wheeled things generally sold at motorcycle dealerships.
It is kind of questionable to have four round profile tires. I get it because they tilt. How come it does not state how many G forces it can pull in a turn?