Comparison of tire sizes 225/55 R17 and 215/45 R18
225/55R17
225
Tire width 
55
Profile height 
R17
Tire diameter 
469
RPM per km 225mm124mm679mm2134mm
225
55
17
215
45
18
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 679 | 651 | -28 (-4.1%) | ||
| Width, mm | 225 | 215 | -10 (-4.4%) | ||
| Circumference, mm | 2134 | 2044 | -90 (-4.2%) | ||
| Profile height, mm | 124 | 97 | -27 (-21.8%) | ||
| RPM per km | 469 | 489 | +20 (+4.3%) | ||
| Clearance change, mm | -14 | ||||
| Result: | The diameter differs by -4.1%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 95.8 |
| Difference (km/h) | -4.2 |
Sizes for comparison of tires 225/55 R17
R17
R16 -1
R18 +1
R15 -2
R19 +2
Sizes for comparison of tires 215/45 R18
R18
R17 -1
R19 +1
R16 -2
R20 +2