215/60R17 vs 235/50R18
235/50R18 is a safe swap for 215/60R17 by the usual ±3% rule: the diameter differs by +0.35%.
Speedometer and odometer
With 235/50R18 on a car calibrated for 215/60R17, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.3%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.2 mph |
| 60 mph | 60.2 mph |
| 70 mph | 70.2 mph |
| 80 mph | 80.3 mph |
Other sizes close to 215/60R17
- 215/60R17 vs 225/50R17-4.78%
- 215/60R17 vs 225/55R17-1.52%
- 215/60R17 vs 235/55R17+0.07%
- 215/60R17 vs 215/55R17-3.12%
- 215/60R17 vs 225/60R17+1.74%
- 215/60R17 vs 215/65R16-0.57%
- 215/60R17 vs 235/60R17+3.48%
- 215/60R17 vs 215/65R17+3.12%
- 215/60R17 vs 235/50R17-3.33%
- 215/60R17 vs 255/45R18-0.45%
- 215/60R17 vs 215/55R18+0.57%
- 215/60R17 vs 235/60R16-0.20%
Questions
Can I replace 215/60R17 with 235/50R18?
235/50R18 is a safe swap for 215/60R17 by the usual ±3% rule: the diameter differs by +0.35%.
What's the difference between 215/60R17 and 235/50R18?
235/50R18 is 0.09" taller and 20 mm wider; the sidewall is -0.45". At an indicated 60 mph you'd actually be doing 60.2 mph.
Will 235/50R18 fit on 215/60R17 wheels?
No — 215/60R17 needs a 17" wheel and 235/50R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.