265/65R18 vs 305/60R18
305/60R18 is a safe swap for 265/65R18 by the usual ±3% rule: the diameter differs by +2.68%.
Speedometer and odometer
With 305/60R18 on a car calibrated for 265/65R18, the speedometer reads 58.4 mph when you're really doing 60, and the odometer under-counts by 2.7%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.8 mph |
| 45 mph | 46.2 mph |
| 60 mph | 61.6 mph |
| 70 mph | 71.9 mph |
| 80 mph | 82.1 mph |
Other sizes close to 265/65R18
- 265/65R18 vs 265/70R17+0.14%
- 265/65R18 vs 275/65R18+1.62%
- 265/65R18 vs 265/60R18-3.31%
- 265/65R18 vs 265/70R18+3.31%
- 265/65R18 vs 235/65R18-4.86%
- 265/65R18 vs 245/75R17-0.30%
- 265/65R18 vs 235/80R17+0.76%
- 265/65R18 vs 255/70R18+1.56%
- 265/65R18 vs 255/65R18-1.62%
- 265/65R18 vs 285/65R18+3.24%
- 265/65R18 vs 255/60R18-4.80%
- 265/65R18 vs 33x12.50R18+4.55%
Questions
Can I replace 265/65R18 with 305/60R18?
305/60R18 is a safe swap for 265/65R18 by the usual ±3% rule: the diameter differs by +2.68%.
What's the difference between 265/65R18 and 305/60R18?
305/60R18 is 0.85" taller and 40 mm wider; the sidewall is +0.42". At an indicated 60 mph you'd actually be doing 61.6 mph.
Will 305/60R18 fit on 265/65R18 wheels?
Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 305 mm tire and the fender clearance.