205/50R17 vs 205/55R16
Switching from 205/50R17 to 205/55R16 decreases the overall diameter by 4.9 mm (0.8%). That is within the usual ±3% guideline.
| 205/50R17 | 205/55R16 | Difference (mm / revs) | |
|---|---|---|---|
| Section width | 205 mm | 205 mm | +0.0 |
| Sidewall height | 102.5 mm | 112.8 mm | +10.3 |
| Rim diameter | 431.8 mm | 406.4 mm | -25.4 |
| Overall diameter | 636.8 mm | 631.9 mm | -4.9 |
| Circumference | 2,000.6 mm | 1,985.2 mm | -15.4 |
| Revolutions | 500 per km | 504 per km | +4.0 |
Speedometer effect
With 205/55R16 fitted on a car calibrated for 205/50R17, the real speed when the speedometer shows:
| Speedometer shows | Actual speed |
|---|---|
| 50 km/h | 49.6 km/h |
| 80 km/h | 79.4 km/h |
| 100 km/h | 99.2 km/h |
| 120 km/h | 119.1 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.
205/50R17 dimensions · 205/55R16 dimensions · Open in calculator