Comparison of tire sizes 275/70 R18 and 275/55 R20
275/70R18
275
Tire width 
70
Profile height 
R18
Tire diameter 
378
RPM per km 275mm193mm842mm2646mm
275
70
18
275
55
20
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 842 | 811 | -31 (-3.7%) | ||
| Width, mm | 275 | 275 | 0 (0%) | ||
| Circumference, mm | 2646 | 2546 | -100 (-3.8%) | ||
| Profile height, mm | 193 | 151 | -42 (-21.8%) | ||
| RPM per km | 378 | 393 | +15 (+4%) | ||
| Clearance change, mm | -16 | ||||
| Result: | The diameter differs by -3.7%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 96.2 |
| Difference (km/h) | -3.8 |
Sizes for comparison of tires 275/70 R18
R18
R17 -1
R16 -2
R20 +2
Sizes for comparison of tires 275/55 R20
R20
R19 -1
R21 +1
R18 -2
R22 +2
