215/50R17 vs 255/45R17
255/45R17 is a safe swap for 215/50R17 by the usual ±3% rule: the diameter differs by +2.24%.
Speedometer and odometer
With 255/45R17 on a car calibrated for 215/50R17, the speedometer reads 58.7 mph when you're really doing 60, and the odometer under-counts by 2.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.7 mph |
| 45 mph | 46.0 mph |
| 60 mph | 61.3 mph |
| 70 mph | 71.6 mph |
| 80 mph | 81.8 mph |
Other sizes close to 215/50R17
- 215/50R17 vs 225/45R17-1.93%
- 215/50R17 vs 245/40R18+0.99%
- 215/50R17 vs 225/50R17+1.55%
- 215/50R17 vs 215/45R17-3.32%
- 215/50R17 vs 205/50R17-1.55%
- 215/50R17 vs 215/55R17+3.32%
- 215/50R17 vs 235/40R18-0.25%
- 215/50R17 vs 235/45R17-0.54%
- 215/50R17 vs 245/45R17+0.85%
- 215/50R17 vs 215/55R16-0.60%
- 215/50R17 vs 205/60R16+0.87%
- 215/50R17 vs 245/40R17-2.94%
Questions
Can I replace 215/50R17 with 255/45R17?
255/45R17 is a safe swap for 215/50R17 by the usual ±3% rule: the diameter differs by +2.24%.
What's the difference between 215/50R17 and 255/45R17?
255/45R17 is 0.57" taller and 40 mm wider; the sidewall is +0.29". At an indicated 60 mph you'd actually be doing 61.3 mph.
Will 255/45R17 fit on 215/50R17 wheels?
Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.