265/45R20 vs 265/50R20
265/50R20 is outside the ±3% rule as a replacement for 265/45R20: the diameter differs by +3.55%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 265/50R20 on a car calibrated for 265/45R20, the speedometer reads 57.9 mph when you're really doing 60, and the odometer under-counts by 3.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.1 mph |
| 45 mph | 46.6 mph |
| 60 mph | 62.1 mph |
| 70 mph | 72.5 mph |
| 80 mph | 82.8 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 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%
- 265/45R20 vs 315/35R20-2.41%
Questions
Can I replace 265/45R20 with 265/50R20?
265/50R20 is outside the ±3% rule as a replacement for 265/45R20: the diameter differs by +3.55%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 265/45R20 and 265/50R20?
265/50R20 is 1.04" taller and 0 mm wider; the sidewall is +0.52". At an indicated 60 mph you'd actually be doing 62.1 mph.
Will 265/50R20 fit on 265/45R20 wheels?
Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 265 mm tire and the fender clearance.