The new tire changes overall diameter by -16.33%. 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 | 33.5 km/h | 25 mph | 21 mph |
| 60 km/h | 50.2 km/h | 37 mph | 31 mph |
| 80 km/h | 66.9 km/h | 50 mph | 42 mph |
| 100 km/h | 83.7 km/h | 62 mph | 52 mph |
| 120 km/h | 100.4 km/h | 75 mph | 62 mph |
Commonly compared with 285/60R18
- 285/60R18 vs 265/65R18 · 265/65R18 specs
- 285/60R18 vs 265/70R17 · 265/70R17 specs
- 285/60R18 vs 255/70R18 · 255/70R18 specs
- 285/60R18 vs 275/65R18 · 275/65R18 specs
- 285/60R18 vs 275/70R17 · 275/70R17 specs
- 285/60R18 vs 265/65R17 · 265/65R17 specs
- 285/60R18 vs 265/60R18 · 265/60R18 specs
- 285/60R18 vs 245/70R17 · 245/70R17 specs
FAQ
What is the overall diameter of a 285/60R18 tire?
A 285/60R18 tire has an overall diameter of about 31.46 inches (799 mm) and a section width of 285 mm.
What sizes can replace a 285/60R18 tire?
Sizes within about ±3% of 285/60R18's 31.5-inch diameter are the closest matches, such as 265/65R18, 265/70R17, 255/70R18. Use the calculator above to check the exact speedometer effect of any substitute.
Fitment & trouble codes
Changing tire size by more than about 3% shifts the speedometer, odometer and, on some vehicles, ABS/traction calibration — which can set wheel-speed-sensor or vehicle-speed codes. See C1234 (wheel speed sensor) and C0050 (rear wheel speed) if a warning light appears after a size change.