CFM vs Diameter

I'm not sure even, how these companies pretend to rate fan airflow. Way too many variables, not the least of which is the construction of the radiator tubes and fins which present restriction to that airflow.

and manufacturers/ relabelers/ resellers can claim ANYTHING in print. This is made clear by things like winch ratings (not true line pull lifting ability) compressor CFM (sometimes rated at suction/ intake instead of at operating pressure, output), or electric motors HP rated not by actual mechanical shaft horsepower, but rather falsely represented by the LINE POWER they draw.