Comparison of tire sizes 255/55 R20 and 255/50 R20
255/55R20
255
Tire width 
55
Profile height 
R20
Tire diameter 
404
RPM per km 255mm140mm789mm2477mm
255
55
20
255
50
20
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 789 | 763 | -26 (-3.3%) | ||
| Width, mm | 255 | 255 | 0 (0%) | ||
| Circumference, mm | 2477 | 2397 | -80 (-3.2%) | ||
| Profile height, mm | 140 | 128 | -12 (-8.6%) | ||
| RPM per km | 404 | 417 | +13 (+3.2%) | ||
| Clearance change, mm | -13 | ||||
| Result: | The diameter differs by -3.3%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 96.8 |
| Difference (km/h) | -3.2 |
Sizes for comparison of tires 255/55 R20
R20
R19 -1
R21 +1
R18 -2
R22 +2
Sizes for comparison of tires 255/50 R20
R20
R19 -1
R21 +1
R18 -2
R22 +2