Comparison of tire sizes 305/50 R20 and 275/55 R20
305/50R20
305
Tire width 
50
Profile height 
R20
Tire diameter 
392
RPM per km 305mm153mm813mm2554mm
305
50
20
275
55
20
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 813 | 811 | -2 (-0.2%) | ||
| Width, mm | 305 | 275 | -30 (-9.8%) | ||
| Circumference, mm | 2554 | 2546 | -8 (-0.3%) | ||
| Profile height, mm | 153 | 151 | -2 (-1.3%) | ||
| RPM per km | 392 | 393 | +1 (+0.3%) | ||
| Clearance change, mm | -1 | ||||
| Result: | The diameter differs by -0.2%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 99.7 |
| Difference (km/h) | -0.3 |
Sizes for comparison of tires 305/50 R20
R20
R19 -1
R21 +1
R18 -2
R22 +2
Sizes for comparison of tires 275/55 R20
R20
R19 -1
R21 +1
R18 -2
R22 +2