245/45R20 vs 225/55R19
225/55R19 is a safe swap for 245/45R20 by the usual ±3% rule: the diameter differs by +0.22%.
Speedometer and odometer
With 225/55R19 on a car calibrated for 245/45R20, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.1 mph |
| 70 mph | 70.2 mph |
| 80 mph | 80.2 mph |
Other sizes close to 245/45R20
- 245/45R20 vs 255/45R20+1.24%
- 245/45R20 vs 275/40R20-0.07%
- 245/45R20 vs 255/50R20+4.74%
- 245/45R20 vs 245/40R20-3.36%
- 245/45R20 vs 245/50R20+3.36%
- 245/45R20 vs 275/45R20+3.71%
- 245/45R20 vs 255/40R20-2.26%
- 245/45R20 vs 275/35R20-3.84%
- 245/45R20 vs 265/45R20+2.47%
- 245/45R20 vs 285/35R20-2.88%
- 245/45R20 vs 315/35R200.00%
- 245/45R20 vs 245/50R19-0.12%
Questions
Can I replace 245/45R20 with 225/55R19?
225/55R19 is a safe swap for 245/45R20 by the usual ±3% rule: the diameter differs by +0.22%.
What's the difference between 245/45R20 and 225/55R19?
225/55R19 is 0.06" taller and 20 mm narrower; the sidewall is +0.53". At an indicated 60 mph you'd actually be doing 60.1 mph.
Will 225/55R19 fit on 245/45R20 wheels?
No — 245/45R20 needs a 20" wheel and 225/55R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.