285/60R20 vs 285/65R20
285/65R20 is outside the ±3% rule as a replacement for 285/60R20: the diameter differs by +3.35%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 285/65R20 on a car calibrated for 285/60R20, the speedometer reads 58.1 mph when you're really doing 60, and the odometer under-counts by 3.4%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.0 mph |
| 45 mph | 46.5 mph |
| 60 mph | 62.0 mph |
| 70 mph | 72.3 mph |
| 80 mph | 82.7 mph |
Other sizes close to 285/60R20
- 285/60R20 vs 275/55R20-4.65%
- 285/60R20 vs 275/60R20-1.41%
- 285/60R20 vs 275/65R20+1.82%
- 285/60R20 vs 35x12.50R20+4.59%
- 285/60R20 vs 265/60R20-2.82%
- 285/60R20 vs 305/55R20-0.76%
- 285/60R20 vs 285/55R20-3.35%
- 285/60R20 vs 33x12.50R20-1.39%
- 285/60R20 vs 295/60R20+1.41%
- 285/60R20 vs 295/55R20-2.06%
- 285/60R20 vs 295/65R20+4.88%
- 285/60R20 vs 305/50R20-4.35%
Questions
Can I replace 285/60R20 with 285/65R20?
285/65R20 is outside the ±3% rule as a replacement for 285/60R20: the diameter differs by +3.35%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 285/60R20 and 285/65R20?
285/65R20 is 1.12" taller and 0 mm wider; the sidewall is +0.56". At an indicated 60 mph you'd actually be doing 62.0 mph.
Will 285/65R20 fit on 285/60R20 wheels?
Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 285 mm tire and the fender clearance.