Comparison of tire sizes 155/70 R12 and 155/65 R13
155/70R12
155
Tire width 
70
Profile height 
R12
Tire diameter 
610
RPM per km 155mm109mm522mm1639mm
155
70
12
155
65
13
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 522 | 532 | +10 (+1.9%) | ||
| Width, mm | 155 | 155 | 0 (0%) | ||
| Circumference, mm | 1639 | 1670 | +31 (+1.9%) | ||
| Profile height, mm | 109 | 101 | -8 (-7.3%) | ||
| RPM per km | 610 | 599 | -11 (-1.8%) | ||
| Clearance change, mm | +5 | ||||
| Result: | The diameter differs by 1.9%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 101.9 |
| Difference (km/h) | 1.9 |
Sizes for comparison of tires 155/70 R12
R12
R13 +1
R14 +2
Sizes for comparison of tires 155/65 R13
R13
R12 -1
R14 +1
