235/60R20 vs 285/45R21 tire size
285/45R21 vs 235/60R20, diameter
Same diameter
- Speedometer
- 60.0 mph
- At a true 60 mph
- Diameter
- 31.10 in
- Was 31.10 in
- Revs per mile
- 649
- Was 648
- 3% guideline
- Within
Car built for 235/60R20, now on 285/45R21.
235/60R20 and 285/45R21
| Measure | 235/60R20 | 285/45R21 | Difference |
|---|---|---|---|
| Width, mm | 235 | 285 | +50 |
| Sidewall, % of width | 60 | 45 | -15 |
| Rim, in | 20 | 21 | +1 |
| Section height, in | 5.55 | 5.05 | -0.50 |
| Diameter, in | 31.10 | 31.10 | 0 (-0.0%) |
| Circumference, in | 97.7 | 97.7 | -0.0 |
| Revs per mile | 648 | 649 | +0 (+0.0%) |
Fitting 285/45R21 instead of 235/60R20
Within the usual 3% diameter guideline.
- Needs 21 in wheels.
- 50 mm wider. Check rubbing at full lock.
- Shorter sidewall: 0.5 in less.
Cars with 235/60R20
Cars with 285/45R21
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