275/40R17 vs 245/50R17
245/50R17 is outside the ±3% rule as a replacement for 275/40R17: the diameter differs by +3.84%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 245/50R17 on a car calibrated for 275/40R17, the speedometer reads 57.8 mph when you're really doing 60, and the odometer under-counts by 3.8%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.2 mph |
| 45 mph | 46.7 mph |
| 60 mph | 62.3 mph |
| 70 mph | 72.7 mph |
| 80 mph | 83.1 mph |
Other sizes close to 275/40R17
- 275/40R17 vs 225/45R17-2.68%
- 275/40R17 vs 245/40R18+0.21%
- 275/40R17 vs 225/50R17+0.77%
- 275/40R17 vs 225/55R17+4.22%
- 275/40R17 vs 215/45R17-4.07%
- 275/40R17 vs 205/50R17-2.30%
- 275/40R17 vs 215/55R17+2.53%
- 275/40R17 vs 215/50R17-0.77%
- 275/40R17 vs 235/45R17-1.30%
- 275/40R17 vs 245/45R17+0.08%
- 275/40R17 vs 205/60R16+0.09%
- 275/40R17 vs 245/40R17-3.68%
Questions
Can I replace 275/40R17 with 245/50R17?
245/50R17 is outside the ±3% rule as a replacement for 275/40R17: the diameter differs by +3.84%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 275/40R17 and 245/50R17?
245/50R17 is 0.98" taller and 30 mm narrower; the sidewall is +0.49". At an indicated 60 mph you'd actually be doing 62.3 mph.
Will 245/50R17 fit on 275/40R17 wheels?
Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 245 mm tire and the fender clearance.