Comparison of tire sizes 255/65 R17 and 225/65 R18
255/65R17
255
Tire width 
65
Profile height 
R17
Tire diameter 
417
RPM per km 255mm166mm763mm2398mm
255
65
17
225
65
18
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 763 | 750 | -13 (-1.7%) | ||
| Width, mm | 255 | 225 | -30 (-11.8%) | ||
| Circumference, mm | 2398 | 2355 | -43 (-1.8%) | ||
| Profile height, mm | 166 | 146 | -20 (-12%) | ||
| RPM per km | 417 | 425 | +8 (+1.9%) | ||
| Clearance change, mm | -7 | ||||
| Result: | The diameter differs by -1.7%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 98.2 |
| Difference (km/h) | -1.8 |
Sizes for comparison of tires 255/65 R17
R17
R16 -1
R18 +1
R15 -2
R19 +2
Sizes for comparison of tires 225/65 R18
R18
R17 -1
R19 +1
R16 -2
R20 +2