175/70R14 vs 195/55R15
Switching from 175/70R14 to 195/55R15 decreases the overall diameter by 5.1 mm (0.8%). That is within the usual ±3% guideline.
| 175/70R14 | 195/55R15 | Difference (mm / revs) | |
|---|---|---|---|
| Section width | 175 mm | 195 mm | +20.0 |
| Sidewall height | 122.5 mm | 107.2 mm | -15.3 |
| Rim diameter | 355.6 mm | 381.0 mm | +25.4 |
| Overall diameter | 600.6 mm | 595.5 mm | -5.1 |
| Circumference | 1,886.8 mm | 1,870.8 mm | -16.0 |
| Revolutions | 530 per km | 535 per km | +5.0 |
Speedometer effect
With 195/55R15 fitted on a car calibrated for 175/70R14, the real speed when the speedometer shows:
| Speedometer shows | Actual speed |
|---|---|
| 50 km/h | 49.6 km/h |
| 80 km/h | 79.3 km/h |
| 100 km/h | 99.2 km/h |
| 120 km/h | 119.0 km/h |
Smaller tires make the speedometer read higher than the actual speed. Most speedometers also read slightly high from the factory.
Before you change size
- Check the sizes approved for your vehicle on the door-jamb placard or in the owner's manual.
- Check clearance to suspension, brakes and arches at full lock and full compression.
- Match or exceed the original load index and speed rating.
- Wider tires need an appropriate rim width; a 195 mm tire has a manufacturer-specified rim width range.
175/70R14 dimensions · 195/55R15 dimensions · Open in calculator