235/60R18 vs 255/55R18 tire size
255/55R18 vs 235/60R18, diameter
-0.2% shorter
- Speedometer
- 60.1 mph
- At a true 60 mph
- Diameter
- 29.04 in
- Was 29.10 in
- Revs per mile
- 694
- Was 693
- 3% guideline
- Within
Car built for 235/60R18, now on 255/55R18.
235/60R18 and 255/55R18
| Measure | 235/60R18 | 255/55R18 | Difference |
|---|---|---|---|
| Width, mm | 235 | 255 | +20 |
| Sidewall, % of width | 60 | 55 | -5 |
| Rim, in | 18 | 18 | 0 |
| Section height, in | 5.55 | 5.52 | -0.03 |
| Diameter, in | 29.10 | 29.04 | -0.06 (-0.2%) |
| Circumference, in | 91.4 | 91.2 | -0.2 |
| Revs per mile | 693 | 694 | +1 (+0.2%) |
Fitting 255/55R18 instead of 235/60R18
Within the usual 3% diameter guideline.
- 20 mm wider. Check rubbing at full lock.
Cars with 235/60R18
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