235/55R18 vs 225/60R18
225/60R18 is a safe swap for 235/55R18 by the usual ±3% rule: the diameter differs by +1.61%.
Speedometer and odometer
With 225/60R18 on a car calibrated for 235/55R18, 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 235/55R18
- 235/55R18 vs 235/60R18+3.28%
- 235/55R18 vs 235/50R18-3.28%
- 235/55R18 vs 225/50R18-4.68%
- 235/55R18 vs 245/60R18+4.96%
- 235/55R18 vs 225/55R18-1.54%
- 235/55R18 vs 255/55R18+3.07%
- 235/55R18 vs 255/45R19-0.50%
- 235/55R18 vs 235/60R17-0.27%
- 235/55R18 vs 215/65R17-0.61%
- 235/55R18 vs 245/50R18-1.89%
- 235/55R18 vs 235/50R19+0.27%
- 235/55R18 vs 255/45R18-4.05%
Questions
Can I replace 235/55R18 with 225/60R18?
225/60R18 is a safe swap for 235/55R18 by the usual ±3% rule: the diameter differs by +1.61%.
What's the difference between 235/55R18 and 225/60R18?
225/60R18 is 0.45" taller and 10 mm narrower; the sidewall is +0.23". At an indicated 60 mph you'd actually be doing 61.0 mph.
Will 225/60R18 fit on 235/55R18 wheels?
Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 225 mm tire and the fender clearance.