+3.35%Borderline — noticeable speedometer/odometer error
Speedometer error
With a speedometer calibrated to 265/75R16, fitting 285/70R17 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 41.3 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 | 103.3 km/h | 62 mph | 64 mph |
| 120 km/h | 124.0 km/h | 75 mph | 77 mph |
Full comparison
265/75R16
Overall diameter803.9 mm · 31.65 in
Section width265 mm · 10.43 in
Sidewall height198.8 mm · 7.82 in
Circumference2525.5 mm · 99.4 in
Revolutions per mile637
Revolutions per km396
285/70R17
Overall diameter830.8 mm · 32.71 in
Section width285 mm · 11.22 in
Sidewall height199.5 mm · 7.85 in
Circumference2610.0 mm · 102.8 in
Revolutions per mile617
Revolutions per km383
+3.35%Borderline — noticeable speedometer/odometer error
Original
Overall diameter803.9 mm · 31.65 in
Sidewall height198.8 mm
Circumference2,525.5 mm
Revolutions / mile637.2
New
Overall diameter830.8 mm · 32.71 in
Sidewall height199.5 mm
Circumference2,610 mm
Revolutions / mile616.6
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 | 41.3 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 | 103.3 km/h | 62 mph | 64 mph |
| 120 km/h | 124 km/h | 75 mph | 77 mph |
See individual specs: 265/75R16 · 285/70R17. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.