235/55R20 vs 275/50R20
275/50R20 is a safe swap for 235/55R20 by the usual ±3% rule: the diameter differs by +2.15%.
Speedometer and odometer
With 275/50R20 on a car calibrated for 235/55R20, the speedometer reads 58.7 mph when you're really doing 60, and the odometer under-counts by 2.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.6 mph |
| 45 mph | 46.0 mph |
| 60 mph | 61.3 mph |
| 70 mph | 71.5 mph |
| 80 mph | 81.7 mph |
Other sizes close to 235/55R20
- 235/55R20 vs 245/45R20-4.96%
- 235/55R20 vs 255/45R20-3.78%
- 235/55R20 vs 255/50R20-0.46%
- 235/55R20 vs 265/50R20+0.85%
- 235/55R20 vs 245/50R20-1.76%
- 235/55R20 vs 275/45R20-1.44%
- 235/55R20 vs 255/55R20+2.87%
- 235/55R20 vs 265/45R20-2.61%
- 235/55R20 vs 255/55R19-0.44%
- 235/55R20 vs 315/35R20-4.96%
- 235/55R20 vs 295/40R20-2.94%
- 235/55R20 vs 285/50R20+3.46%
Questions
Can I replace 235/55R20 with 275/50R20?
275/50R20 is a safe swap for 235/55R20 by the usual ±3% rule: the diameter differs by +2.15%.
What's the difference between 235/55R20 and 275/50R20?
275/50R20 is 0.65" taller and 40 mm wider; the sidewall is +0.32". At an indicated 60 mph you'd actually be doing 61.3 mph.
Will 275/50R20 fit on 235/55R20 wheels?
Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.