245/55R18 vs 235/60R18
235/60R18 is a safe swap for 245/55R18 by the usual ±3% rule: the diameter differs by +1.72%.
Speedometer and odometer
With 235/60R18 on a car calibrated for 245/55R18, the speedometer reads 59.0 mph when you're really doing 60, and the odometer under-counts by 1.7%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.5 mph |
| 45 mph | 45.8 mph |
| 60 mph | 61.0 mph |
| 70 mph | 71.2 mph |
| 80 mph | 81.4 mph |
Other sizes close to 245/55R18
- 245/55R18 vs 225/65R17-0.33%
- 245/55R18 vs 235/50R18-4.75%
- 245/55R18 vs 235/55R18-1.51%
- 245/55R18 vs 225/60R18+0.07%
- 245/55R18 vs 245/60R18+3.37%
- 245/55R18 vs 225/55R18-3.03%
- 245/55R18 vs 255/55R18+1.51%
- 245/55R18 vs 235/65R18+4.95%
- 245/55R18 vs 225/55R19+0.47%
- 245/55R18 vs 245/50R18-3.37%
- 245/55R18 vs 215/55R18-4.54%
- 245/55R18 vs 245/50R19+0.12%
Questions
Can I replace 245/55R18 with 235/60R18?
235/60R18 is a safe swap for 245/55R18 by the usual ±3% rule: the diameter differs by +1.72%.
What's the difference between 245/55R18 and 235/60R18?
235/60R18 is 0.49" taller and 10 mm narrower; the sidewall is +0.25". At an indicated 60 mph you'd actually be doing 61.0 mph.
Will 235/60R18 fit on 245/55R18 wheels?
Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 235 mm tire and the fender clearance.