235/65R17 vs 255/55R18 tire size
255/55R18 vs 235/65R17, diameter
Same diameter
- Speedometer
- 60.0 mph
- At a true 60 mph
- Diameter
- 29.04 in
- Was 29.03 in
- Revs per mile
- 694
- Was 695
- 3% guideline
- Within
Car built for 235/65R17, now on 255/55R18.
235/65R17 and 255/55R18
| Measure | 235/65R17 | 255/55R18 | Difference |
|---|---|---|---|
| Width, mm | 235 | 255 | +20 |
| Sidewall, % of width | 65 | 55 | -10 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 6.01 | 5.52 | -0.49 |
| Diameter, in | 29.03 | 29.04 | +0.02 (+0.1%) |
| Circumference, in | 91.2 | 91.2 | +0.0 |
| Revs per mile | 695 | 694 | -0 (-0.1%) |
Fitting 255/55R18 instead of 235/65R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
- 20 mm wider. Check rubbing at full lock.
Cars with 235/65R17
Cars with 255/55R18
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