265/50R20 vs 255/55R20
255/55R20 is a safe swap for 265/50R20 by the usual ±3% rule: the diameter differs by +2.01%.
Speedometer and odometer
With 255/55R20 on a car calibrated for 265/50R20, the speedometer reads 58.8 mph when you're really doing 60, and the odometer under-counts by 2.0%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.6 mph |
| 45 mph | 45.9 mph |
| 60 mph | 61.2 mph |
| 70 mph | 71.4 mph |
| 80 mph | 81.6 mph |
Other sizes close to 265/50R20
- 265/50R20 vs 275/55R20+4.85%
- 265/50R20 vs 255/45R20-4.59%
- 265/50R20 vs 255/50R20-1.29%
- 265/50R20 vs 245/50R20-2.59%
- 265/50R20 vs 275/45R20-2.26%
- 265/50R20 vs 235/55R20-0.84%
- 265/50R20 vs 265/45R20-3.43%
- 265/50R20 vs 275/50R20+1.29%
- 265/50R20 vs 295/40R20-3.75%
- 265/50R20 vs 285/50R20+2.59%
- 265/50R20 vs 295/40R21-0.47%
- 265/50R20 vs 285/40R20-4.79%
Questions
Can I replace 265/50R20 with 255/55R20?
255/55R20 is a safe swap for 265/50R20 by the usual ±3% rule: the diameter differs by +2.01%.
What's the difference between 265/50R20 and 255/55R20?
255/55R20 is 0.61" taller and 10 mm narrower; the sidewall is +0.31". At an indicated 60 mph you'd actually be doing 61.2 mph.
Will 255/55R20 fit on 265/50R20 wheels?
Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.