245/50R18 vs 245/45R19
245/45R19 is a safe swap for 245/50R18 by the usual ±3% rule: the diameter differs by +0.13%.
Speedometer and odometer
With 245/45R19 on a car calibrated for 245/50R18, 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 245/50R18
- 245/50R18 vs 245/45R18-3.49%
- 245/50R18 vs 235/50R18-1.42%
- 245/50R18 vs 235/55R18+1.92%
- 245/50R18 vs 235/45R18-4.77%
- 245/50R18 vs 225/60R18+3.56%
- 245/50R18 vs 225/50R18-2.85%
- 245/50R18 vs 225/60R17-0.06%
- 245/50R18 vs 225/55R18+0.36%
- 245/50R18 vs 275/40R19+0.06%
- 245/50R18 vs 255/45R18-2.21%
- 245/50R18 vs 215/55R18-1.21%
- 245/50R18 vs 275/40R18-3.56%
Questions
Can I replace 245/50R18 with 245/45R19?
245/45R19 is a safe swap for 245/50R18 by the usual ±3% rule: the diameter differs by +0.13%.
What's the difference between 245/50R18 and 245/45R19?
245/45R19 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 245/45R19 fit on 245/50R18 wheels?
No — 245/50R18 needs a 18" wheel and 245/45R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.