295/40R20 vs 235/45R21 tire size
235/45R21 vs 295/40R20, diameter
+0.1% taller
- Speedometer
- 59.9 mph
- At a true 60 mph
- Diameter
- 29.33 in
- Was 29.29 in
- Revs per mile
- 688
- Was 689
- 3% guideline
- Within
Car built for 295/40R20, now on 235/45R21.
295/40R20 and 235/45R21
| Measure | 295/40R20 | 235/45R21 | Difference |
|---|---|---|---|
| Width, mm | 295 | 235 | -60 |
| Sidewall, % of width | 40 | 45 | +5 |
| Rim, in | 20 | 21 | +1 |
| Section height, in | 4.65 | 4.16 | -0.48 |
| Diameter, in | 29.29 | 29.33 | +0.04 (+0.1%) |
| Circumference, in | 92.0 | 92.1 | +0.1 |
| Revs per mile | 689 | 688 | -1 (-0.1%) |
Fitting 235/45R21 instead of 295/40R20
Within the usual 3% diameter guideline.
- Needs 21 in wheels.
Cars with 235/45R21
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