245/60R18 vs 235/65R18
235/65R18 is a safe swap for 245/60R18 by the usual ±3% rule: the diameter differs by +1.53%.
Speedometer and odometer
With 235/65R18 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 1.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.5 mph |
| 45 mph | 45.7 mph |
| 60 mph | 60.9 mph |
| 70 mph | 71.1 mph |
| 80 mph | 81.2 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 245/55R19+0.12%
- 245/60R18 vs 255/65R18+4.99%
- 245/60R18 vs 265/50R19-0.48%
- 245/60R18 vs 255/60R18+1.60%
- 245/60R18 vs 245/55R18-3.26%
- 245/60R18 vs 275/60R18+4.79%
Questions
Can I replace 245/60R18 with 235/65R18?
235/65R18 is a safe swap for 245/60R18 by the usual ±3% rule: the diameter differs by +1.53%.
What's the difference between 245/60R18 and 235/65R18?
235/65R18 is 0.45" taller and 10 mm narrower; the sidewall is +0.23". At an indicated 60 mph you'd actually be doing 60.9 mph.
Will 235/65R18 fit on 245/60R18 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.