185/70R14 vs 205/50R16
Switching from 185/70R14 to 205/50R16 decreases the overall diameter by 3.2 mm (0.5%). That is within the usual ±3% guideline.
| 185/70R14 | 205/50R16 | Difference (mm / revs) | |
|---|---|---|---|
| Section width | 185 mm | 205 mm | +20.0 |
| Sidewall height | 129.5 mm | 102.5 mm | -27.0 |
| Rim diameter | 355.6 mm | 406.4 mm | +50.8 |
| Overall diameter | 614.6 mm | 611.4 mm | -3.2 |
| Circumference | 1,930.8 mm | 1,920.8 mm | -10.0 |
| Revolutions | 518 per km | 521 per km | +3.0 |
Speedometer effect
With 205/50R16 fitted on a car calibrated for 185/70R14, the real speed when the speedometer shows:
| Speedometer shows | Actual speed |
|---|---|
| 50 km/h | 49.7 km/h |
| 80 km/h | 79.6 km/h |
| 100 km/h | 99.5 km/h |
| 120 km/h | 119.4 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 205 mm tire has a manufacturer-specified rim width range.
185/70R14 dimensions · 205/50R16 dimensions · Open in calculator