Comparison of tire sizes 145/70 R12 and 145/70 R13

145/70R12
145 Tire width
70 Profile height
R12 Tire diameter
627 RPM per km
145mm102mm508mm1595mm
145
70
12
145
70
13
Parameters Sizes Old New
Diameter, mm508533+25 (+4.9%)
Width, mm1451450 (0%)
Circumference, mm15951675+80 (+5%)
Profile height, mm1021020 (0%)
RPM per km627597-30 (-4.8%)
Clearance change, mm+13
Result:
The diameter differs by 4.9%.
Speedometer reading (km/h)
Real speed (km/h)105
Difference (km/h)5

Sizes for comparison of tires 145/70 R12

R12
R13 +1

Sizes for comparison of tires 145/70 R13

R13
R12 -1
R14 +1