Comparison of tire sizes 155/70 R12 and 165/65 R13

155/70R12
155 Tire width
70 Profile height
R12 Tire diameter
610 RPM per km
155mm109mm522mm1639mm
155
70
12
165
65
13
Parameters Sizes Old New
Diameter, mm522545+23 (+4.4%)
Width, mm155165+10 (+6.5%)
Circumference, mm16391711+72 (+4.4%)
Profile height, mm109107-2 (-1.8%)
RPM per km610584-26 (-4.3%)
Clearance change, mm+12
Result:
The diameter differs by 4.4%.
Speedometer reading (km/h)
Real speed (km/h)104.4
Difference (km/h)4.4

Sizes for comparison of tires 155/70 R12

R12
R13 +1
R14 +2

Sizes for comparison of tires 165/65 R13

R13
R14 +1
R15 +2