Focus-AK and lasitter (and anyone else who views this thread).
Be very careful!
When you go to compare tires for your vehicle, they have to be tested at the same conditions. The data in the charts above is
NOT. Different sizes are tested at different loads. If you want to compare different sized tires, you should be looking at RRC values (RRF divided by the test load) - and if you do, you will find that wider tires are ever so slightly better for RR. See my web page for a more detailed discussion:
Barry's Tire Tech
PLUS, the data in the above charts is for a single line of identical tires (except for size). The tires happen to be non-LRR, but that doesn't matter. What you should be getting from the data is the relative values for different sized tires.