+6.62%Not recommended — recalibrate the speedometer
Speedometer error
With a speedometer calibrated to 185/60R15, fitting 215/55R16 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 42.6 km/h | 25 mph | 26 mph |
| 60 km/h | 64.0 km/h | 37 mph | 40 mph |
| 80 km/h | 85.3 km/h | 50 mph | 53 mph |
| 100 km/h | 106.6 km/h | 62 mph | 66 mph |
| 120 km/h | 127.9 km/h | 75 mph | 79 mph |
Full comparison
185/60R15
Overall diameter603.0 mm · 23.74 in
Section width185 mm · 7.28 in
Sidewall height111.0 mm · 4.37 in
Circumference1894.4 mm · 74.6 in
Revolutions per mile850
Revolutions per km528
215/55R16
Overall diameter642.9 mm · 25.31 in
Section width215 mm · 8.46 in
Sidewall height118.3 mm · 4.66 in
Circumference2019.7 mm · 79.5 in
Revolutions per mile797
Revolutions per km495
+6.62%Not recommended — recalibrate the speedometer
Original
Overall diameter603 mm · 23.74 in
Sidewall height111 mm
Circumference1,894.4 mm
Revolutions / mile849.5
New
Overall diameter642.9 mm · 25.31 in
Sidewall height118.3 mm
Circumference2,019.7 mm
Revolutions / mile796.8
Speedometer & odometer error
The new tire changes overall diameter by +6.62%. 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 | 42.6 km/h | 25 mph | 26 mph |
| 60 km/h | 64 km/h | 37 mph | 40 mph |
| 80 km/h | 85.3 km/h | 50 mph | 53 mph |
| 100 km/h | 106.6 km/h | 62 mph | 66 mph |
| 120 km/h | 127.9 km/h | 75 mph | 79 mph |
See individual specs: 185/60R15 · 215/55R16. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.