285/40R20 vs 325/35R20 tire size
325/35R20 vs 285/40R20, diameter
Same diameter
- Speedometer
- 60.0 mph
- At a true 60 mph
- Diameter
- 28.96 in
- Was 28.98 in
- Revs per mile
- 696
- Was 696
- 3% guideline
- Within
Car built for 285/40R20, now on 325/35R20.
285/40R20 and 325/35R20
| Measure | 285/40R20 | 325/35R20 | Difference |
|---|---|---|---|
| Width, mm | 285 | 325 | +40 |
| Sidewall, % of width | 40 | 35 | -5 |
| Rim, in | 20 | 20 | 0 |
| Section height, in | 4.49 | 4.48 | -0.01 |
| Diameter, in | 28.98 | 28.96 | -0.02 (-0.1%) |
| Circumference, in | 91.0 | 91.0 | -0.1 |
| Revs per mile | 696 | 696 | +0 (+0.1%) |
Fitting 325/35R20 instead of 285/40R20
Within the usual 3% diameter guideline.
- 40 mm wider. Check rubbing at full lock.
Cars with 285/40R20
Cars with 325/35R20
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