265/45R20 vs 275/50R20
275/50R20 is outside the ±3% rule as a replacement for 265/45R20: the diameter differs by +4.89%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 275/50R20 on a car calibrated for 265/45R20, the speedometer reads 57.2 mph when you're really doing 60, and the odometer under-counts by 4.9%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.5 mph |
| 45 mph | 47.2 mph |
| 60 mph | 62.9 mph |
| 70 mph | 73.4 mph |
| 80 mph | 83.9 mph |
Other sizes close to 265/45R20
- 265/45R20 vs 235/55R19-0.72%
- 265/45R20 vs 245/45R20-2.41%
- 265/45R20 vs 255/45R20-1.21%
- 265/45R20 vs 255/50R20+2.21%
- 265/45R20 vs 275/40R20-2.48%
- 265/45R20 vs 265/50R20+3.55%
- 265/45R20 vs 245/50R20+0.87%
- 265/45R20 vs 275/45R20+1.21%
- 265/45R20 vs 235/55R20+2.68%
- 265/45R20 vs 255/40R20-4.62%
- 265/45R20 vs 245/55R19+0.75%
- 265/45R20 vs 265/50R19+0.15%
Questions
Can I replace 265/45R20 with 275/50R20?
275/50R20 is outside the ±3% rule as a replacement for 265/45R20: the diameter differs by +4.89%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 265/45R20 and 275/50R20?
275/50R20 is 1.44" taller and 10 mm wider; the sidewall is +0.72". At an indicated 60 mph you'd actually be doing 62.9 mph.
Will 275/50R20 fit on 265/45R20 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.