Comparison of tire sizes 255/65 R18 and 245/75 R16
255/65R18
255
Tire width 
65
Profile height 
R18
Tire diameter 
404
RPM per km 255mm166mm789mm2478mm
255
65
18
245
75
16
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 789 | 774 | -15 (-1.9%) | ||
| Width, mm | 255 | 245 | -10 (-3.9%) | ||
| Circumference, mm | 2478 | 2431 | -47 (-1.9%) | ||
| Profile height, mm | 166 | 184 | +18 (+10.8%) | ||
| RPM per km | 404 | 411 | +7 (+1.7%) | ||
| Clearance change, mm | -8 | ||||
| Result: | The diameter differs by -1.9%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 98.1 |
| Difference (km/h) | -1.9 |
Sizes for comparison of tires 255/65 R18
R18
R17 -1
R19 +1
R16 -2
R20 +2
Sizes for comparison of tires 245/75 R16
R16
R15 -1
R17 +1
R18 +2