Comparison of tire sizes 235/45 R17 and 245/40 R17
235/45R17
235
Tire width 
45
Profile height 
R17
Tire diameter 
495
RPM per km 235mm106mm643mm2021mm
235
45
17
245
40
17
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 643 | 628 | -15 (-2.3%) | ||
| Width, mm | 235 | 245 | +10 (+4.3%) | ||
| Circumference, mm | 2021 | 1972 | -49 (-2.4%) | ||
| Profile height, mm | 106 | 98 | -8 (-7.5%) | ||
| RPM per km | 495 | 507 | +12 (+2.4%) | ||
| Clearance change, mm | -8 | ||||
| Result: | The diameter differs by -2.3%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 97.6 |
| Difference (km/h) | -2.4 |
Sizes for comparison of tires 235/45 R17
R17
R16 -1
R18 +1
R15 -2
R19 +2
Sizes for comparison of tires 245/40 R17
R17
R16 -1
R18 +1
R15 -2
R19 +2