replaced the 18" wheels and tires on their newer 2500 truck with 16" to get away from height and fifth wheel clearance issues. Don't know why the new trucks are so tall but my newer (2015) is 58" tal...
Most Dually wheels are 17" now, I would not go to 16"s again. The primary reason for the increase wheel size is the calipers like others have said. I would address the issue in another way.