+3.39%Borderline — noticeable speedometer/odometer error
Speedometer error
With a speedometer calibrated to 245/70R16, fitting 245/70R17 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 41.4 km/h | 25 mph | 26 mph |
| 60 km/h | 62.0 km/h | 37 mph | 39 mph |
| 80 km/h | 82.7 km/h | 50 mph | 51 mph |
| 100 km/h | 103.4 km/h | 62 mph | 64 mph |
| 120 km/h | 124.1 km/h | 75 mph | 77 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
245/70R17
Overall diameter774.8 mm · 30.50 in
Section width245 mm · 9.65 in
Sidewall height171.5 mm · 6.75 in
Circumference2434.1 mm · 95.8 in
Revolutions per mile661
Revolutions per km411
+3.39%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 diameter774.8 mm · 30.5 in
Sidewall height171.5 mm
Circumference2,434.1 mm
Revolutions / mile661.2
Speedometer & odometer error
The new tire changes overall diameter by +3.39%. 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 | 41.4 km/h | 25 mph | 26 mph |
| 60 km/h | 62 km/h | 37 mph | 39 mph |
| 80 km/h | 82.7 km/h | 50 mph | 51 mph |
| 100 km/h | 103.4 km/h | 62 mph | 64 mph |
| 120 km/h | 124.1 km/h | 75 mph | 77 mph |
See individual specs: 245/70R16 · 245/70R17. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.