Question: how to measure centric ring?
Answer: The size of the centric rim depends on two things: the center bore of the rim and the outer diameter of the car's wheel hub. For example, if the diameter of the wheel hub is 72.6 mm, and the wheel center bore is 74.1 mm, a centric ring with a diameter of 1.5 mm is needed in-between, so the right size is 74.1 - 72.6 mm.