285/75R18 vs 325/65R18 tire size
325/65R18 vs 285/75R18, diameter
-0.6% shorter
- Speedometer
- 60.3 mph
- At a true 60 mph
- Diameter
- 34.63 in
- Was 34.83 in
- Revs per mile
- 582
- Was 579
- 3% guideline
- Within
Car built for 285/75R18, now on 325/65R18.
285/75R18 and 325/65R18
| Measure | 285/75R18 | 325/65R18 | Difference |
|---|---|---|---|
| Width, mm | 285 | 325 | +40 |
| Sidewall, % of width | 75 | 65 | -10 |
| Rim, in | 18 | 18 | 0 |
| Section height, in | 8.42 | 8.32 | -0.10 |
| Diameter, in | 34.83 | 34.63 | -0.20 (-0.6%) |
| Circumference, in | 109.4 | 108.8 | -0.6 |
| Revs per mile | 579 | 582 | +3 (+0.6%) |
Fitting 325/65R18 instead of 285/75R18
Within the usual 3% diameter guideline.
- 40 mm wider. Check rubbing at full lock.
Cars with 285/75R18
Cars with 325/65R18
What this cannot tell you
Diameter within 3% is a common shop guideline, not a maker spec.
Load index, offset and clearance are not in this data.
- Two or more sources agree
- One source
- Model-level or estimate
- Sources differ