+0.28%Safe swap — speedometer error is minor
Speedometer error
With a speedometer calibrated to 235/60R16, fitting 235/55R17 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 40.1 km/h | 25 mph | 25 mph |
| 60 km/h | 60.2 km/h | 37 mph | 37 mph |
| 80 km/h | 80.2 km/h | 50 mph | 50 mph |
| 100 km/h | 100.3 km/h | 62 mph | 62 mph |
| 120 km/h | 120.3 km/h | 75 mph | 75 mph |
Full comparison
235/60R16
Overall diameter688.4 mm · 27.10 in
Section width235 mm · 9.25 in
Sidewall height141.0 mm · 5.55 in
Circumference2162.7 mm · 85.1 in
Revolutions per mile744
Revolutions per km462
235/55R17
Overall diameter690.3 mm · 27.18 in
Section width235 mm · 9.25 in
Sidewall height129.3 mm · 5.09 in
Circumference2168.6 mm · 85.4 in
Revolutions per mile742
Revolutions per km461
+0.28%Safe swap — speedometer error is minor
Original
Overall diameter688.4 mm · 27.1 in
Sidewall height141 mm
Circumference2,162.7 mm
Revolutions / mile744.1
New
Overall diameter690.3 mm · 27.18 in
Sidewall height129.3 mm
Circumference2,168.6 mm
Revolutions / mile742.1
Speedometer & odometer error
The new tire changes overall diameter by +0.28%. With a speedometer calibrated to the original tire, that same percentage is how far the speedometer and odometer read off — a taller tire means your true speed is higher than indicated and the odometer under-counts distance.
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 40.1 km/h | 25 mph | 25 mph |
| 60 km/h | 60.2 km/h | 37 mph | 37 mph |
| 80 km/h | 80.2 km/h | 50 mph | 50 mph |
| 100 km/h | 100.3 km/h | 62 mph | 62 mph |
| 120 km/h | 120.3 km/h | 75 mph | 75 mph |
See individual specs: 235/60R16 · 235/55R17. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.