I wonder if they have any real road data on the rim/tire discussion we're having here. If 22 are grippier and heavier, certainly they will reduce range. If we know 21 is the most efficient, we just need to ask about 20 and 22...I'll see if I can get customer service to answer that20” will be a softer ride. They’ve stated the 21” will be the most efficient, but to my knowledge haven’t stated whether the 22” or 20” are more or less efficient than the other. They have said the 22” are “grippier”, meaning higher rolling resistance and less efficient, both whether the aggressive AT tread of the 20} is even less efficient than that is unknown. Good chance it will be.
Rim size has nothing to do with rotations per mile. That’s a factor of the outside dimension of the tire. The 20” is the largest of the three by 1.2” OD. I think the weight of the wheel and tire combined and the rolling resistance will impact efficient more than tire size.