-3.35%Borderline — noticeable speedometer/odometer error
Speedometer error
With a speedometer calibrated to 245/70R16, fitting 225/65R17 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 38.7 km/h | 25 mph | 24 mph |
| 60 km/h | 58.0 km/h | 37 mph | 36 mph |
| 80 km/h | 77.3 km/h | 50 mph | 48 mph |
| 100 km/h | 96.7 km/h | 62 mph | 60 mph |
| 120 km/h | 116.0 km/h | 75 mph | 72 mph |
Full comparison
245/70R16
Overall diameter749.4 mm · 29.50 in
Section width245 mm · 9.65 in
Sidewall height171.5 mm · 6.75 in
Circumference2354.3 mm · 92.7 in
Revolutions per mile684
Revolutions per km425
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
-3.35%Borderline — noticeable speedometer/odometer error
Original
Overall diameter749.4 mm · 29.5 in
Sidewall height171.5 mm
Circumference2,354.3 mm
Revolutions / mile683.6
New
Overall diameter724.3 mm · 28.52 in
Sidewall height146.3 mm
Circumference2,275.5 mm
Revolutions / mile707.3
Speedometer & odometer error
The new tire changes overall diameter by -3.35%. 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 | 38.7 km/h | 25 mph | 24 mph |
| 60 km/h | 58 km/h | 37 mph | 36 mph |
| 80 km/h | 77.3 km/h | 50 mph | 48 mph |
| 100 km/h | 96.7 km/h | 62 mph | 60 mph |
| 120 km/h | 116 km/h | 75 mph | 72 mph |
See individual specs: 245/70R16 · 225/65R17. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.