Remember, this is a
guide. Slight bending of accepted practice should be OK.
Rim Width in Inches ------ Maximum Tire Width
6" ------ 9.50" Max
7" ------ 9.50"-10.50"
8" ------ 10.50"-11.50"
8.5" ------ 10.50"-12.50"
10" ------ 12.50" and Up
P-Metric Size ------ Actual Tire Width ------ Actual Tire Height
15-inch rims
205/70R15 ------ 8.7 inches ------ 26.2 inches
215/75R15 ------ 8.46 inches ------ 27.6 inches
235/75R15 ------ 9.25 inches ------ 28.8 inches
265/70R15 ------ 10.4 inches ------ 29.6 inches
16-inch rims
245/75R16 ------ 9.64 inches ------ 30.4 inches
285/75R16 ------ 11.2 inches ------ 32.8 inches
315/75R16 ------ 12.4 inches ------ 34.6 inches
395/70R16 ------ 15.5 inches ------ 37.7 inches
17-inch rims
235/65R17 ------ 9.25 inches ------ 29.5 inches
265/70R17 ------ 10.4 inches ------ 31.6 inches
255/75R17 ------ 10.4 inches ------ 32.0 inches
285/70R17 ------ 11.2 inches ------ 32.7 inches
315/70R17 ------ 12.4 inches ------ 34.3 inches
This is a nice guide too.