+1.53%Safe swap — speedometer error is minor
Speedometer error
With a speedometer calibrated to 225/65R17, fitting 235/70R16 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 40.6 km/h | 25 mph | 25 mph |
| 60 km/h | 60.9 km/h | 37 mph | 38 mph |
| 80 km/h | 81.2 km/h | 50 mph | 50 mph |
| 100 km/h | 101.5 km/h | 62 mph | 63 mph |
| 120 km/h | 121.8 km/h | 75 mph | 76 mph |
Full comparison
225/65R17
Overall diameter724.3 mm · 28.52 in
Section width225 mm · 8.86 in
Sidewall height146.3 mm · 5.76 in
Circumference2275.5 mm · 89.6 in
Revolutions per mile707
Revolutions per km439
235/70R16
Overall diameter735.4 mm · 28.95 in
Section width235 mm · 9.25 in
Sidewall height164.5 mm · 6.48 in
Circumference2310.3 mm · 91.0 in
Revolutions per mile697
Revolutions per km433
+1.53%Safe swap — speedometer error is minor
Original
Overall diameter724.3 mm · 28.52 in
Sidewall height146.3 mm
Circumference2,275.5 mm
Revolutions / mile707.3
New
Overall diameter735.4 mm · 28.95 in
Sidewall height164.5 mm
Circumference2,310.3 mm
Revolutions / mile696.6
Speedometer & odometer error
The new tire changes overall diameter by +1.53%. 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 | 40.6 km/h | 25 mph | 25 mph |
| 60 km/h | 60.9 km/h | 37 mph | 38 mph |
| 80 km/h | 81.2 km/h | 50 mph | 50 mph |
| 100 km/h | 101.5 km/h | 62 mph | 63 mph |
| 120 km/h | 121.8 km/h | 75 mph | 76 mph |
See individual specs: 225/65R17 · 235/70R16. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.