Comparison of tire sizes 275/55 R17 and 285/55 R18

275/55R17
275 Tire width
55 Profile height
R17 Tire diameter
433 RPM per km
275mm151mm734mm2307mm
275
55
17
285
55
18
Parameters Sizes Old New
Diameter, mm734771+37 (+5%)
Width, mm275285+10 (+3.6%)
Circumference, mm23072421+114 (+4.9%)
Profile height, mm151157+6 (+4%)
RPM per km433413-20 (-4.6%)
Clearance change, mm+19
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 275/55 R17

R17
R16 -1
R18 +1
R15 -2
R19 +2

Sizes for comparison of tires 285/55 R18

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