235/65R17 vs 255/65R17
255/65R17 is outside the ±3% rule as a replacement for 235/65R17: the diameter differs by +3.53%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 255/65R17 on a car calibrated for 235/65R17, the speedometer reads 58.0 mph when you're really doing 60, and the odometer under-counts by 3.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.1 mph |
| 45 mph | 46.6 mph |
| 60 mph | 62.1 mph |
| 70 mph | 72.5 mph |
| 80 mph | 82.8 mph |
Other sizes close to 235/65R17
- 235/65R17 vs 235/60R18+0.26%
- 235/65R17 vs 225/65R17-1.76%
- 235/65R17 vs 225/60R17-4.81%
- 235/65R17 vs 245/65R17+1.76%
- 235/65R17 vs 255/55R18+0.05%
- 235/65R17 vs 225/75R16+0.90%
- 235/65R17 vs 235/70R16-0.26%
- 235/65R17 vs 235/60R17-3.19%
- 235/65R17 vs 215/65R17-3.53%
- 235/65R17 vs 235/70R17+3.19%
- 235/65R17 vs 255/65R16+0.08%
- 235/65R17 vs 255/60R17+0.07%
Questions
Can I replace 235/65R17 with 255/65R17?
255/65R17 is outside the ±3% rule as a replacement for 235/65R17: the diameter differs by +3.53%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 235/65R17 and 255/65R17?
255/65R17 is 1.02" taller and 20 mm wider; the sidewall is +0.51". At an indicated 60 mph you'd actually be doing 62.1 mph.
Will 255/65R17 fit on 235/65R17 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.