+1.06%Safe swap — speedometer error is minor
Speedometer error
With a speedometer calibrated to 215/45R17, fitting 205/55R16 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 40.4 km/h | 25 mph | 25 mph |
| 60 km/h | 60.6 km/h | 37 mph | 38 mph |
| 80 km/h | 80.8 km/h | 50 mph | 50 mph |
| 100 km/h | 101.1 km/h | 62 mph | 63 mph |
| 120 km/h | 121.3 km/h | 75 mph | 75 mph |
Full comparison
215/45R17
Overall diameter625.3 mm · 24.62 in
Section width215 mm · 8.46 in
Sidewall height96.8 mm · 3.81 in
Circumference1964.4 mm · 77.3 in
Revolutions per mile819
Revolutions per km509
205/55R16
Overall diameter631.9 mm · 24.88 in
Section width205 mm · 8.07 in
Sidewall height112.8 mm · 4.44 in
Circumference1985.2 mm · 78.2 in
Revolutions per mile811
Revolutions per km504
+1.06%Safe swap — speedometer error is minor
Original
Overall diameter625.3 mm · 24.62 in
Sidewall height96.8 mm
Circumference1,964.4 mm
Revolutions / mile819.2
New
Overall diameter631.9 mm · 24.88 in
Sidewall height112.8 mm
Circumference1,985.2 mm
Revolutions / mile810.7
Speedometer & odometer error
The new tire changes overall diameter by +1.06%. 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 | 40.4 km/h | 25 mph | 25 mph |
| 60 km/h | 60.6 km/h | 37 mph | 38 mph |
| 80 km/h | 80.8 km/h | 50 mph | 50 mph |
| 100 km/h | 101.1 km/h | 62 mph | 63 mph |
| 120 km/h | 121.3 km/h | 75 mph | 75 mph |
See individual specs: 215/45R17 · 205/55R16. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.