Comparison of tire sizes 185/60 R15 and 185/55 R15

185
60
15
185
55
15
185/60R15
tire
185 Tire width
60 Profile height
R15 Tire diameter
RPM per km
tire
185mm111mm603mm1894mm528
Parameters Sizes Old New
Diameter, mm603585-18 (-3%)
Width, mm1851850 (0%)
Circumference, mm18941836-58 (-3.1%)
Profile height, mm111102-9 (-8.1%)
RPM per km528545+17 (+3.2%)
Clearance change, mm-9
Speedometer reading (km/h)96.9-3.1
Result:
The diameter differs by -3%.

Sizes for comparison of tires 185/60 R15

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