Tire size vs wheel width

mvh said
The data tables in the Tire Rack tire description pages also list the manufacturers recommended rim widths for each size of tire.

Yep, this is just to add some clarity on which end of that range is best.

DionR said
I would guess the issue with the widest tire on the rim not being the fastest is because the tire is pinched and probably loses some tread contact with the asphalt. Plus, the tread is probably able to squirm more sideways on the wheel compared to a narrower tire that better fits the rim. Just my theories though.

Agree. Makes sense when you consider the subjective responses too.