-4.31%Borderline — noticeable speedometer/odometer error
Speedometer error
With a speedometer calibrated to 225/70R16, fitting 235/55R17 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 38.3 km/h | 25 mph | 24 mph |
| 60 km/h | 57.4 km/h | 37 mph | 36 mph |
| 80 km/h | 76.6 km/h | 50 mph | 48 mph |
| 100 km/h | 95.7 km/h | 62 mph | 59 mph |
| 120 km/h | 114.8 km/h | 75 mph | 71 mph |
Full comparison
225/70R16
Overall diameter721.4 mm · 28.40 in
Section width225 mm · 8.86 in
Sidewall height157.5 mm · 6.20 in
Circumference2266.3 mm · 89.2 in
Revolutions per mile710
Revolutions per km441
235/55R17
Overall diameter690.3 mm · 27.18 in
Section width235 mm · 9.25 in
Sidewall height129.3 mm · 5.09 in
Circumference2168.6 mm · 85.4 in
Revolutions per mile742
Revolutions per km461
-4.31%Borderline — noticeable speedometer/odometer error
Original
Overall diameter721.4 mm · 28.4 in
Sidewall height157.5 mm
Circumference2,266.3 mm
Revolutions / mile710.1
New
Overall diameter690.3 mm · 27.18 in
Sidewall height129.3 mm
Circumference2,168.6 mm
Revolutions / mile742.1
Speedometer & odometer error
The new tire changes overall diameter by -4.31%. 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 | 38.3 km/h | 25 mph | 24 mph |
| 60 km/h | 57.4 km/h | 37 mph | 36 mph |
| 80 km/h | 76.6 km/h | 50 mph | 48 mph |
| 100 km/h | 95.7 km/h | 62 mph | 59 mph |
| 120 km/h | 114.8 km/h | 75 mph | 71 mph |
See individual specs: 225/70R16 · 235/55R17. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.