Comparison of tire sizes 135/80 R13 and 155/70 R12

135/80R13
135 Tire width
80 Profile height
R13 Tire diameter
583 RPM per km
135mm108mm546mm1716mm
135
80
13
155
70
12
Parameters Sizes Old New
Diameter, mm546522-24 (-4.4%)
Width, mm135155+20 (+14.8%)
Circumference, mm17161639-77 (-4.5%)
Profile height, mm108109+1 (+0.9%)
RPM per km583610+27 (+4.6%)
Clearance change, mm-12
Result:
The diameter differs by -4.4%.
Speedometer reading (km/h)
Real speed (km/h)95.5
Difference (km/h)-4.5

Sizes for comparison of tires 135/80 R13

R13
R14 +1
R15 +2

Sizes for comparison of tires 155/70 R12

R12
R13 +1
R14 +2