Comparison of tire sizes 155/70 R12 and 135/80 R13
155/70R12
155
Tire width 
70
Profile height 
R12
Tire diameter 
610
RPM per km 155mm109mm522mm1639mm
155
70
12
135
80
13
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 522 | 546 | +24 (+4.6%) | ||
| Width, mm | 155 | 135 | -20 (-12.9%) | ||
| Circumference, mm | 1639 | 1716 | +77 (+4.7%) | ||
| Profile height, mm | 109 | 108 | -1 (-0.9%) | ||
| RPM per km | 610 | 583 | -27 (-4.4%) | ||
| Clearance change, mm | +12 | ||||
| Result: | The diameter differs by 4.6%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 104.7 |
| Difference (km/h) | 4.7 |
Sizes for comparison of tires 155/70 R12
R12
R13 +1
R14 +2
Sizes for comparison of tires 135/80 R13
R13
R14 +1
R15 +2