+0.83%Safe swap — speedometer error is minor
Speedometer error
With a speedometer calibrated to 225/60R16, fitting 215/70R15 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 40.3 km/h | 25 mph | 25 mph |
| 60 km/h | 60.5 km/h | 37 mph | 38 mph |
| 80 km/h | 80.7 km/h | 50 mph | 50 mph |
| 100 km/h | 100.8 km/h | 62 mph | 63 mph |
| 120 km/h | 121.0 km/h | 75 mph | 75 mph |
Full comparison
225/60R16
Overall diameter676.4 mm · 26.63 in
Section width225 mm · 8.86 in
Sidewall height135.0 mm · 5.31 in
Circumference2125.0 mm · 83.7 in
Revolutions per mile757
Revolutions per km471
215/70R15
Overall diameter682.0 mm · 26.85 in
Section width215 mm · 8.46 in
Sidewall height150.5 mm · 5.93 in
Circumference2142.6 mm · 84.4 in
Revolutions per mile751
Revolutions per km467
+0.83%Safe swap — speedometer error is minor
Original
Overall diameter676.4 mm · 26.63 in
Sidewall height135 mm
Circumference2,125 mm
Revolutions / mile757.3
New
Overall diameter682 mm · 26.85 in
Sidewall height150.5 mm
Circumference2,142.6 mm
Revolutions / mile751.1
Speedometer & odometer error
The new tire changes overall diameter by +0.83%. 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 | 40.3 km/h | 25 mph | 25 mph |
| 60 km/h | 60.5 km/h | 37 mph | 38 mph |
| 80 km/h | 80.7 km/h | 50 mph | 50 mph |
| 100 km/h | 100.8 km/h | 62 mph | 63 mph |
| 120 km/h | 121 km/h | 75 mph | 75 mph |
See individual specs: 225/60R16 · 215/70R15. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.