245/50R19 vs 245/45R20
245/45R20 is a safe swap for 245/50R19 by the usual ±3% rule: the diameter differs by +0.12%.
Speedometer and odometer
With 245/45R20 on a car calibrated for 245/50R19, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.1%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.0 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.1 mph |
| 70 mph | 70.1 mph |
| 80 mph | 80.1 mph |
Other sizes close to 245/50R19
- 245/50R19 vs 235/55R19+1.86%
- 245/50R19 vs 245/45R19-3.37%
- 245/50R19 vs 225/60R18-0.05%
- 245/50R19 vs 255/50R19+1.37%
- 245/50R19 vs 275/40R20+0.05%
- 245/50R19 vs 255/45R19-2.13%
- 245/50R19 vs 225/55R19+0.34%
- 245/50R19 vs 275/40R19-3.44%
- 245/50R19 vs 235/50R19-1.37%
- 245/50R19 vs 245/55R19+3.37%
- 245/50R19 vs 255/55R19+4.88%
- 245/50R19 vs 235/45R19-4.60%
Questions
Can I replace 245/50R19 with 245/45R20?
245/45R20 is a safe swap for 245/50R19 by the usual ±3% rule: the diameter differs by +0.12%.
What's the difference between 245/50R19 and 245/45R20?
245/45R20 is 0.04" taller and 0 mm wider; the sidewall is -0.48". At an indicated 60 mph you'd actually be doing 60.1 mph.
Will 245/45R20 fit on 245/50R19 wheels?
No — 245/50R19 needs a 19" wheel and 245/45R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.