Comparison of tire sizes 155/65 R14 and 185/55 R15

155/65R14
155 Tire width
65 Profile height
R14 Tire diameter
571 RPM per km
155mm101mm557mm1750mm
155
65
14
185
55
15
Parameters Sizes Old New
Diameter, mm557585+28 (+5%)
Width, mm155185+30 (+19.4%)
Circumference, mm17501836+86 (+4.9%)
Profile height, mm101102+1 (+1%)
RPM per km571545-26 (-4.6%)
Clearance change, mm+14
Result:
The diameter differs by 5%.
Speedometer reading (km/h)
Real speed (km/h)104.9
Difference (km/h)4.9

Sizes for comparison of tires 155/65 R14

R14
R13 -1
R15 +1
R16 +2

Sizes for comparison of tires 185/55 R15

R15
R14 -1
R16 +1
R13 -2
R17 +2