275/65R20 vs 285/65R20
285/65R20 is a safe swap for 275/65R20 by the usual ±3% rule: the diameter differs by +1.50%.
Speedometer and odometer
With 285/65R20 on a car calibrated for 275/65R20, the speedometer reads 59.1 mph when you're really doing 60, and the odometer under-counts by 1.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.5 mph |
| 45 mph | 45.7 mph |
| 60 mph | 60.9 mph |
| 70 mph | 71.1 mph |
| 80 mph | 81.2 mph |
Other sizes close to 275/65R20
- 275/65R20 vs 275/60R20-3.18%
- 275/65R20 vs 35x12.50R20+2.72%
- 275/65R20 vs 265/60R20-4.56%
- 275/65R20 vs 305/55R20-2.54%
- 275/65R20 vs 285/60R20-1.79%
- 275/65R20 vs 33x12.50R20-3.15%
- 275/65R20 vs 295/60R20-0.40%
- 275/65R20 vs 295/55R20-3.81%
- 275/65R20 vs 295/65R20+3.00%
- 275/65R20 vs 325/60R20+3.76%
- 275/65R20 vs 35x11.50R20+2.72%
- 275/65R20 vs 35x13.50R20+2.72%
Questions
Can I replace 275/65R20 with 285/65R20?
285/65R20 is a safe swap for 275/65R20 by the usual ±3% rule: the diameter differs by +1.50%.
What's the difference between 275/65R20 and 285/65R20?
285/65R20 is 0.51" taller and 10 mm wider; the sidewall is +0.26". At an indicated 60 mph you'd actually be doing 60.9 mph.
Will 285/65R20 fit on 275/65R20 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.