285/40R20 vs 295/35R21 tire size
295/35R21 vs 285/40R20, diameter
+0.5% taller
- Speedometer
- 59.7 mph
- At a true 60 mph
- Diameter
- 29.13 in
- Was 28.98 in
- Revs per mile
- 692
- Was 696
- 3% guideline
- Within
Car built for 285/40R20, now on 295/35R21.
285/40R20 and 295/35R21
| Measure | 285/40R20 | 295/35R21 | Difference |
|---|---|---|---|
| Width, mm | 285 | 295 | +10 |
| Sidewall, % of width | 40 | 35 | -5 |
| Rim, in | 20 | 21 | +1 |
| Section height, in | 4.49 | 4.06 | -0.42 |
| Diameter, in | 28.98 | 29.13 | +0.15 (+0.5%) |
| Circumference, in | 91.0 | 91.5 | +0.5 |
| Revs per mile | 696 | 692 | -4 (-0.5%) |
Fitting 295/35R21 instead of 285/40R20
Within the usual 3% diameter guideline.
- Needs 21 in wheels.
Cars with 285/40R20
Cars with 295/35R21
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