275/45R18 vs 215/65R17
215/65R17 is a safe swap for 275/45R18 by the usual ±3% rule: the diameter differs by +0.94%.
Speedometer and odometer
With 215/65R17 on a car calibrated for 275/45R18, 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 275/45R18
- 275/45R18 vs 235/60R18+4.90%
- 275/45R18 vs 245/45R18-3.83%
- 275/45R18 vs 235/50R18-1.77%
- 275/45R18 vs 235/55R18+1.56%
- 275/45R18 vs 245/45R19-0.23%
- 275/45R18 vs 225/60R18+3.19%
- 275/45R18 vs 225/50R18-3.19%
- 275/45R18 vs 225/60R17-0.41%
- 275/45R18 vs 225/55R180.00%
- 275/45R18 vs 255/55R18+4.68%
- 275/45R18 vs 275/40R19-0.30%
- 275/45R18 vs 245/50R18-0.35%
Questions
Can I replace 275/45R18 with 215/65R17?
215/65R17 is a safe swap for 275/45R18 by the usual ±3% rule: the diameter differs by +0.94%.
What's the difference between 275/45R18 and 215/65R17?
215/65R17 is 0.26" taller and 60 mm narrower; the sidewall is +0.63". At an indicated 60 mph you'd actually be doing 60.6 mph.
Will 215/65R17 fit on 275/45R18 wheels?
No — 275/45R18 needs a 18" wheel and 215/65R17 a 17" wheel. This is a plus/minus-size swap that changes wheels too.