215/45R18 vs 225/50R17
225/50R17 is a safe swap for 215/45R18 by the usual ±3% rule: the diameter differs by +0.94%.
Speedometer and odometer
With 225/50R17 on a car calibrated for 215/45R18, the speedometer reads 59.4 mph when you're really doing 60, and the odometer under-counts by 0.9%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.3 mph |
| 45 mph | 45.4 mph |
| 60 mph | 60.6 mph |
| 70 mph | 70.7 mph |
| 80 mph | 80.7 mph |
Other sizes close to 215/45R18
- 215/45R18 vs 245/40R18+0.38%
- 215/45R18 vs 225/45R18+1.38%
- 215/45R18 vs 225/40R18-2.07%
- 215/45R18 vs 245/45R18+4.15%
- 215/45R18 vs 235/45R18+2.77%
- 215/45R18 vs 235/40R18-0.85%
- 215/45R18 vs 225/50R18+4.84%
- 215/45R18 vs 215/50R17-0.60%
- 215/45R18 vs 245/45R17+0.25%
- 215/45R18 vs 255/35R18-2.31%
- 215/45R18 vs 255/40R18+1.61%
- 215/45R18 vs 245/35R19+0.52%
Questions
Can I replace 215/45R18 with 225/50R17?
225/50R17 is a safe swap for 215/45R18 by the usual ±3% rule: the diameter differs by +0.94%.
What's the difference between 215/45R18 and 225/50R17?
225/50R17 is 0.24" taller and 10 mm wider; the sidewall is +0.62". At an indicated 60 mph you'd actually be doing 60.6 mph.
Will 225/50R17 fit on 215/45R18 wheels?
No — 215/45R18 needs a 18" wheel and 225/50R17 a 17" wheel. This is a plus/minus-size swap that changes wheels too.