-2.54%Safe swap — speedometer error is minor
Speedometer error
With a speedometer calibrated to 215/60R16, fitting 205/65R15 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 39.0 km/h | 25 mph | 24 mph |
| 60 km/h | 58.5 km/h | 37 mph | 36 mph |
| 80 km/h | 78.0 km/h | 50 mph | 48 mph |
| 100 km/h | 97.5 km/h | 62 mph | 61 mph |
| 120 km/h | 116.9 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
205/65R15
Overall diameter647.5 mm · 25.49 in
Section width205 mm · 8.07 in
Sidewall height133.3 mm · 5.25 in
Circumference2034.2 mm · 80.1 in
Revolutions per mile791
Revolutions per km492
-2.54%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 diameter647.5 mm · 25.49 in
Sidewall height133.3 mm
Circumference2,034.2 mm
Revolutions / mile791.2
Speedometer & odometer error
The new tire changes overall diameter by -2.54%. 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 km/h | 25 mph | 24 mph |
| 60 km/h | 58.5 km/h | 37 mph | 36 mph |
| 80 km/h | 78 km/h | 50 mph | 48 mph |
| 100 km/h | 97.5 km/h | 62 mph | 61 mph |
| 120 km/h | 116.9 km/h | 75 mph | 73 mph |
See individual specs: 215/60R16 · 205/65R15. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.