235/55R19 vs 285/40R20 tire size
285/40R20 vs 235/55R19, diameter
-0.7% shorter
- Speedometer
- 60.4 mph
- At a true 60 mph
- Diameter
- 28.98 in
- Was 29.18 in
- Revs per mile
- 696
- Was 691
- 3% guideline
- Within
Car built for 235/55R19, now on 285/40R20.
235/55R19 and 285/40R20
| Measure | 235/55R19 | 285/40R20 | Difference |
|---|---|---|---|
| Width, mm | 235 | 285 | +50 |
| Sidewall, % of width | 55 | 40 | -15 |
| Rim, in | 19 | 20 | +1 |
| Section height, in | 5.09 | 4.49 | -0.60 |
| Diameter, in | 29.18 | 28.98 | -0.20 (-0.7%) |
| Circumference, in | 91.7 | 91.0 | -0.6 |
| Revs per mile | 691 | 696 | +5 (+0.7%) |
Fitting 285/40R20 instead of 235/55R19
Within the usual 3% diameter guideline.
- Needs 20 in wheels.
- 50 mm wider. Check rubbing at full lock.
- Shorter sidewall: 0.6 in less.
Cars with 235/55R19
Cars with 285/40R20
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