225/50R18 vs 225/45R19
225/45R19 is a safe swap for 225/50R18 by the usual ±3% rule: the diameter differs by +0.43%.
Speedometer and odometer
With 225/45R19 on a car calibrated for 225/50R18, the speedometer reads 59.7 mph when you're really doing 60, and the odometer under-counts by 0.4%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.2 mph |
| 60 mph | 60.3 mph |
| 70 mph | 70.3 mph |
| 80 mph | 80.3 mph |
Other sizes close to 225/50R18
- 225/50R18 vs 225/45R18-3.30%
- 225/50R18 vs 245/40R18-4.25%
- 225/50R18 vs 225/55R17-0.43%
- 225/50R18 vs 245/45R18-0.66%
- 225/50R18 vs 235/50R18+1.47%
- 225/50R18 vs 235/45R18-1.98%
- 225/50R18 vs 235/55R18+4.91%
- 225/50R18 vs 245/40R19-0.53%
- 225/50R18 vs 255/40R19+0.64%
- 225/50R18 vs 225/55R18+3.30%
- 225/50R18 vs 255/40R18-3.08%
- 225/50R18 vs 245/50R18+2.93%
Questions
Can I replace 225/50R18 with 225/45R19?
225/45R19 is a safe swap for 225/50R18 by the usual ±3% rule: the diameter differs by +0.43%.
What's the difference between 225/50R18 and 225/45R19?
225/45R19 is 0.11" taller and 0 mm wider; the sidewall is -0.44". At an indicated 60 mph you'd actually be doing 60.3 mph.
Will 225/45R19 fit on 225/50R18 wheels?
No — 225/50R18 needs a 18" wheel and 225/45R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.