Comparison of tire sizes 315/25 R20 and 345/30 R19
315/25R20
315
Tire width 
25
Profile height 
R20
Tire diameter 
478
RPM per km 315mm79mm666mm2091mm
315
25
20
345
30
19
| Parameters Sizes | Old | New | |||
|---|---|---|---|---|---|
| Diameter, mm | 666 | 690 | +24 (+3.6%) | ||
| Width, mm | 315 | 345 | +30 (+9.5%) | ||
| Circumference, mm | 2091 | 2166 | +75 (+3.6%) | ||
| Profile height, mm | 79 | 104 | +25 (+31.6%) | ||
| RPM per km | 478 | 462 | -16 (-3.3%) | ||
| Clearance change, mm | +12 | ||||
| Result: | The diameter differs by 3.6%. | ||||
| Speedometer reading (km/h) | |
|---|---|
| Real speed (km/h) | 103.6 |
| Difference (km/h) | 3.6 |
Sizes for comparison of tires 315/25 R20
R20
R19 -1
R21 +1
R18 -2
Sizes for comparison of tires 345/30 R19
R19
R18 -1
R20 +1
R17 -2