245/60R18 vs 255/60R18
255/60R18 is a safe swap for 245/60R18 by the usual ±3% rule: the diameter differs by +1.60%.
Speedometer and odometer
With 255/60R18 on a car calibrated for 245/60R18, the speedometer reads 59.1 mph when you're really doing 60, and the odometer under-counts by 1.6%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.5 mph |
| 45 mph | 45.7 mph |
| 60 mph | 61.0 mph |
| 70 mph | 71.1 mph |
| 80 mph | 81.3 mph |
Other sizes close to 245/60R18
- 245/60R18 vs 235/60R18-1.60%
- 245/60R18 vs 235/55R18-4.73%
- 245/60R18 vs 265/60R18+3.19%
- 245/60R18 vs 225/60R18-3.19%
- 245/60R18 vs 245/65R17-0.12%
- 245/60R18 vs 255/55R18-1.80%
- 245/60R18 vs 235/65R18+1.53%
- 245/60R18 vs 245/55R19+0.12%
- 245/60R18 vs 255/65R18+4.99%
- 245/60R18 vs 265/50R19-0.48%
- 245/60R18 vs 245/55R18-3.26%
- 245/60R18 vs 275/60R18+4.79%
Questions
Can I replace 245/60R18 with 255/60R18?
255/60R18 is a safe swap for 245/60R18 by the usual ±3% rule: the diameter differs by +1.60%.
What's the difference between 245/60R18 and 255/60R18?
255/60R18 is 0.47" taller and 10 mm wider; the sidewall is +0.24". At an indicated 60 mph you'd actually be doing 61.0 mph.
Will 255/60R18 fit on 245/60R18 wheels?
Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.