Comparison of tire sizes 285/70 R17 and 285/60 R18

285/70R17
285 Tire width
70 Profile height
R17 Tire diameter
383 RPM per km
285mm200mm831mm2610mm
285
70
17
285
60
18
Parameters Sizes Old New
Diameter, mm831799-32 (-3.9%)
Width, mm2852850 (0%)
Circumference, mm26102511-99 (-3.8%)
Profile height, mm200171-29 (-14.5%)
RPM per km383398+15 (+3.9%)
Clearance change, mm-16
Result:
The diameter differs by -3.9%.
Speedometer reading (km/h)
Real speed (km/h)96.2
Difference (km/h)-3.8

Sizes for comparison of tires 285/70 R17

R17
R16 -1
R18 +1

Sizes for comparison of tires 285/60 R18

R18
R17 -1
R19 +1
R16 -2
R20 +2