265/50R20 vs 265/45R21 tire size
265/45R21 vs 265/50R20, diameter
-0.1% shorter
- Speedometer
- 60.1 mph
- At a true 60 mph
- Diameter
- 30.39 in
- Was 30.43 in
- Revs per mile
- 664
- Was 663
- 3% guideline
- Within
Car built for 265/50R20, now on 265/45R21.
265/50R20 and 265/45R21
| Measure | 265/50R20 | 265/45R21 | Difference |
|---|---|---|---|
| Width, mm | 265 | 265 | 0 |
| Sidewall, % of width | 50 | 45 | -5 |
| Rim, in | 20 | 21 | +1 |
| Section height, in | 5.22 | 4.69 | -0.52 |
| Diameter, in | 30.43 | 30.39 | -0.04 (-0.1%) |
| Circumference, in | 95.6 | 95.5 | -0.1 |
| Revs per mile | 663 | 664 | +1 (+0.1%) |
Fitting 265/45R21 instead of 265/50R20
Within the usual 3% diameter guideline.
- Needs 21 in wheels.
- Shorter sidewall: 0.5 in less.
Cars with 265/50R20
Cars with 265/45R21
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