+5.51%Not recommended — recalibrate the speedometer
Speedometer error
With a speedometer calibrated to 235/75R15, fitting 245/75R16 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 42.2 km/h | 25 mph | 26 mph |
| 60 km/h | 63.3 km/h | 37 mph | 39 mph |
| 80 km/h | 84.4 km/h | 50 mph | 52 mph |
| 100 km/h | 105.5 km/h | 62 mph | 66 mph |
| 120 km/h | 126.6 km/h | 75 mph | 79 mph |
Full comparison
235/75R15
Overall diameter733.5 mm · 28.88 in
Section width235 mm · 9.25 in
Sidewall height176.3 mm · 6.94 in
Circumference2304.4 mm · 90.7 in
Revolutions per mile698
Revolutions per km434
245/75R16
Overall diameter773.9 mm · 30.47 in
Section width245 mm · 9.65 in
Sidewall height183.8 mm · 7.23 in
Circumference2431.3 mm · 95.7 in
Revolutions per mile662
Revolutions per km411
+5.51%Not recommended — recalibrate the speedometer
Original
Overall diameter733.5 mm · 28.88 in
Sidewall height176.3 mm
Circumference2,304.4 mm
Revolutions / mile698.4
New
Overall diameter773.9 mm · 30.47 in
Sidewall height183.8 mm
Circumference2,431.3 mm
Revolutions / mile661.9
Speedometer & odometer error
The new tire changes overall diameter by +5.51%. 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 | 42.2 km/h | 25 mph | 26 mph |
| 60 km/h | 63.3 km/h | 37 mph | 39 mph |
| 80 km/h | 84.4 km/h | 50 mph | 52 mph |
| 100 km/h | 105.5 km/h | 62 mph | 66 mph |
| 120 km/h | 126.6 km/h | 75 mph | 79 mph |
See individual specs: 235/75R15 · 245/75R16. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.