275/60R18 vs 255/70R17
255/70R17 is a safe swap for 275/60R18 by the usual ±3% rule: the diameter differs by +0.20%.
Speedometer and odometer
With 255/70R17 on a car calibrated for 275/60R18, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.1 mph |
| 70 mph | 70.1 mph |
| 80 mph | 80.2 mph |
Other sizes close to 275/60R18
- 275/60R18 vs 275/65R18+3.49%
- 275/60R18 vs 265/60R18-1.52%
- 275/60R18 vs 245/60R18-4.57%
- 275/60R18 vs 265/65R18+1.84%
- 275/60R18 vs 235/65R18-3.11%
- 275/60R18 vs 255/70R18+3.43%
- 275/60R18 vs 255/65R18+0.19%
- 275/60R18 vs 255/60R19+0.18%
- 275/60R18 vs 255/60R18-3.05%
- 275/60R18 vs 235/75R17-0.37%
- 275/60R18 vs 285/60R18+1.52%
- 275/60R18 vs 275/55R19-0.27%
Questions
Can I replace 275/60R18 with 255/70R17?
255/70R17 is a safe swap for 275/60R18 by the usual ±3% rule: the diameter differs by +0.20%.
What's the difference between 275/60R18 and 255/70R17?
255/70R17 is 0.06" taller and 20 mm narrower; the sidewall is +0.53". At an indicated 60 mph you'd actually be doing 60.1 mph.
Will 255/70R17 fit on 275/60R18 wheels?
No — 275/60R18 needs a 18" wheel and 255/70R17 a 17" wheel. This is a plus/minus-size swap that changes wheels too.