Comparison of tire sizes 255/70 R18 and 275/60 R18
255/70R18
255
Tire width 
70
Profile height 
R18
Tire diameter 
391
RPM per km 255mm179mm814mm2558mm
255
70
18
275
60
18
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 814 | 787 | -27 (-3.3%) | ||
| Width, mm | 255 | 275 | +20 (+7.8%) | ||
| Circumference, mm | 2558 | 2473 | -85 (-3.3%) | ||
| Profile height, mm | 179 | 165 | -14 (-7.8%) | ||
| RPM per km | 391 | 404 | +13 (+3.3%) | ||
| Clearance change, mm | -14 | ||||
| Result: | The diameter differs by -3.3%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 96.7 |
| Difference (km/h) | -3.3 |
Sizes for comparison of tires 255/70 R18
R18
R17 -1
R19 +1
R16 -2
R20 +2
Sizes for comparison of tires 275/60 R18
R18
R17 -1
R19 +1
R16 -2
R20 +2