255/75R17 vs 275/65R18
275/65R18 is a safe swap for 255/75R17 by the usual ±3% rule: the diameter differs by +0.05%.
Speedometer and odometer
With 275/65R18 on a car calibrated for 255/75R17, the speedometer reads 60.0 mph when you're really doing 60, and the odometer under-counts by 0.0%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.0 mph |
| 45 mph | 45.0 mph |
| 60 mph | 60.0 mph |
| 70 mph | 70.0 mph |
| 80 mph | 80.0 mph |
Other sizes close to 255/75R17
- 255/75R17 vs 265/70R17-1.41%
- 255/75R17 vs 245/70R17-4.85%
- 255/75R17 vs 285/70R17+2.03%
- 255/75R17 vs 245/75R17-1.84%
- 255/75R17 vs 265/65R17-4.67%
- 255/75R17 vs 235/80R17-0.80%
- 255/75R17 vs 255/70R18-0.01%
- 255/75R17 vs 255/70R17-3.13%
- 255/75R17 vs 295/70R17+3.75%
- 255/75R17 vs 235/75R17-3.68%
- 255/75R17 vs 33x12.50R17+2.94%
- 255/75R17 vs 275/70R17+0.31%
Questions
Can I replace 255/75R17 with 275/65R18?
275/65R18 is a safe swap for 255/75R17 by the usual ±3% rule: the diameter differs by +0.05%.
What's the difference between 255/75R17 and 275/65R18?
275/65R18 is 0.02" taller and 20 mm wider; the sidewall is -0.49". At an indicated 60 mph you'd actually be doing 60.0 mph.
Will 275/65R18 fit on 255/75R17 wheels?
No — 255/75R17 needs a 17" wheel and 275/65R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.