265/65R18 vs 33x12.50R18
33x12.50R18 is outside the ±3% rule as a replacement for 265/65R18: the diameter differs by +4.55%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Side by side
| 265/65R18 | 33x12.50R18 | Difference | |
|---|---|---|---|
| Overall diameter | 31.56" | 33.00" | +1.44" (+4.55%) |
| Section width | 265 mm | 318 mm | +53 mm |
| Sidewall | 6.78" | 7.50" | +0.72" |
| Rim | 18" | 18" | same |
| Circumference | 99.2" | 103.7" | +4.5" |
| Revs per mile | 639 | 611 | -28 |
| Ride height | — | — | +0.72" |
| Speedometer reads 60 mph | 60.0 | 62.7 | +2.7 mph |
Speedometer and odometer
With 33x12.50R18 on a car calibrated for 265/65R18, the speedometer reads 57.4 mph when you're really doing 60, and the odometer under-counts by 4.6%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.4 mph |
| 45 mph | 47.0 mph |
| 60 mph | 62.7 mph |
| 70 mph | 73.2 mph |
| 80 mph | 83.6 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 285/60R18-0.31%
Questions
Can I replace 265/65R18 with 33x12.50R18?
33x12.50R18 is outside the ±3% rule as a replacement for 265/65R18: the diameter differs by +4.55%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 265/65R18 and 33x12.50R18?
33x12.50R18 is 1.44" taller and 53 mm wider; the sidewall is +0.72". At an indicated 60 mph you'd actually be doing 62.7 mph.
Will 33x12.50R18 fit on 265/65R18 wheels?
Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 318 mm tire and the fender clearance.