-1.82%Safe swap — speedometer error is minor
Speedometer error
With a speedometer calibrated to 215/60R16, fitting 245/45R17 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 39.3 km/h | 25 mph | 24 mph |
| 60 km/h | 58.9 km/h | 37 mph | 37 mph |
| 80 km/h | 78.5 km/h | 50 mph | 49 mph |
| 100 km/h | 98.2 km/h | 62 mph | 61 mph |
| 120 km/h | 117.8 km/h | 75 mph | 73 mph |
Full comparison
215/60R16
Overall diameter664.4 mm · 26.16 in
Section width215 mm · 8.46 in
Sidewall height129.0 mm · 5.08 in
Circumference2087.3 mm · 82.2 in
Revolutions per mile771
Revolutions per km479
245/45R17
Overall diameter652.3 mm · 25.68 in
Section width245 mm · 9.65 in
Sidewall height110.3 mm · 4.34 in
Circumference2049.3 mm · 80.7 in
Revolutions per mile785
Revolutions per km488
-1.82%Safe swap — speedometer error is minor
Original
Overall diameter664.4 mm · 26.16 in
Sidewall height129 mm
Circumference2,087.3 mm
Revolutions / mile771
New
Overall diameter652.3 mm · 25.68 in
Sidewall height110.3 mm
Circumference2,049.3 mm
Revolutions / mile785.3
Speedometer & odometer error
The new tire changes overall diameter by -1.82%. 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 | 39.3 km/h | 25 mph | 24 mph |
| 60 km/h | 58.9 km/h | 37 mph | 37 mph |
| 80 km/h | 78.5 km/h | 50 mph | 49 mph |
| 100 km/h | 98.2 km/h | 62 mph | 61 mph |
| 120 km/h | 117.8 km/h | 75 mph | 73 mph |
See individual specs: 215/60R16 · 245/45R17. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.