235/55R19 vs 265/45R20
265/45R20 is a safe swap for 235/55R19 by the usual ±3% rule: the diameter differs by +0.73%.
Speedometer and odometer
With 265/45R20 on a car calibrated for 235/55R19, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.3 mph |
| 60 mph | 60.4 mph |
| 70 mph | 70.5 mph |
| 80 mph | 80.6 mph |
Other sizes close to 235/55R19
- 235/55R19 vs 235/60R18-0.26%
- 235/55R19 vs 255/45R20-0.49%
- 235/55R19 vs 255/50R19-0.47%
- 235/55R19 vs 255/55R18-0.46%
- 235/55R19 vs 255/45R19-3.91%
- 235/55R19 vs 225/55R19-1.48%
- 235/55R19 vs 235/50R19-3.17%
- 235/55R19 vs 245/55R19+1.48%
- 235/55R19 vs 255/55R19+2.97%
- 235/55R19 vs 265/50R19+0.88%
- 235/55R19 vs 245/50R19-1.82%
- 235/55R19 vs 295/40R20+0.39%
Questions
Can I replace 235/55R19 with 265/45R20?
265/45R20 is a safe swap for 235/55R19 by the usual ±3% rule: the diameter differs by +0.73%.
What's the difference between 235/55R19 and 265/45R20?
265/45R20 is 0.21" taller and 30 mm wider; the sidewall is -0.39". At an indicated 60 mph you'd actually be doing 60.4 mph.
Will 265/45R20 fit on 235/55R19 wheels?
No — 235/55R19 needs a 19" wheel and 265/45R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.