+5.77%Not recommended — recalibrate the speedometer
Speedometer error
With a speedometer calibrated to 265/40R22, fitting 285/45R22 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 42.3 km/h | 25 mph | 26 mph |
| 60 km/h | 63.5 km/h | 37 mph | 39 mph |
| 80 km/h | 84.6 km/h | 50 mph | 53 mph |
| 100 km/h | 105.8 km/h | 62 mph | 66 mph |
| 120 km/h | 126.9 km/h | 75 mph | 79 mph |
Full comparison
265/40R22
Overall diameter770.8 mm · 30.35 in
Section width265 mm · 10.43 in
Sidewall height106.0 mm · 4.17 in
Circumference2421.5 mm · 95.3 in
Revolutions per mile665
Revolutions per km413
285/45R22
Overall diameter815.3 mm · 32.10 in
Section width285 mm · 11.22 in
Sidewall height128.3 mm · 5.05 in
Circumference2561.3 mm · 100.8 in
Revolutions per mile628
Revolutions per km390
+5.77%Not recommended — recalibrate the speedometer
Original
Overall diameter770.8 mm · 30.35 in
Sidewall height106 mm
Circumference2,421.5 mm
Revolutions / mile664.6
New
Overall diameter815.3 mm · 32.1 in
Sidewall height128.3 mm
Circumference2,561.3 mm
Revolutions / mile628.3
Speedometer & odometer error
The new tire changes overall diameter by +5.77%. 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 | 42.3 km/h | 25 mph | 26 mph |
| 60 km/h | 63.5 km/h | 37 mph | 39 mph |
| 80 km/h | 84.6 km/h | 50 mph | 53 mph |
| 100 km/h | 105.8 km/h | 62 mph | 66 mph |
| 120 km/h | 126.9 km/h | 75 mph | 79 mph |
See individual specs: 265/40R22 · 285/45R22. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.