255/60R17 vs 235/60R18 tire size
235/60R18 vs 255/60R17, diameter
+0.2% taller
- Speedometer
- 59.9 mph
- At a true 60 mph
- Diameter
- 29.10 in
- Was 29.05 in
- Revs per mile
- 693
- Was 694
- 3% guideline
- Within
Car built for 255/60R17, now on 235/60R18.
255/60R17 and 235/60R18
| Measure | 255/60R17 | 235/60R18 | Difference |
|---|---|---|---|
| Width, mm | 255 | 235 | -20 |
| Sidewall, % of width | 60 | 60 | 0 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 6.02 | 5.55 | -0.47 |
| Diameter, in | 29.05 | 29.10 | +0.06 (+0.2%) |
| Circumference, in | 91.3 | 91.4 | +0.2 |
| Revs per mile | 694 | 693 | -1 (-0.2%) |
Fitting 235/60R18 instead of 255/60R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
Cars with 255/60R17
Cars with 235/60R18
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