235/60R17 vs 255/50R18 tire size
255/50R18 vs 235/60R17, diameter
-0.2% shorter
- Speedometer
- 60.1 mph
- At a true 60 mph
- Diameter
- 28.04 in
- Was 28.10 in
- Revs per mile
- 719
- Was 718
- 3% guideline
- Within
Car built for 235/60R17, now on 255/50R18.
235/60R17 and 255/50R18
| Measure | 235/60R17 | 255/50R18 | Difference |
|---|---|---|---|
| Width, mm | 235 | 255 | +20 |
| Sidewall, % of width | 60 | 50 | -10 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 5.55 | 5.02 | -0.53 |
| Diameter, in | 28.10 | 28.04 | -0.06 (-0.2%) |
| Circumference, in | 88.3 | 88.1 | -0.2 |
| Revs per mile | 718 | 719 | +2 (+0.2%) |
Fitting 255/50R18 instead of 235/60R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
- 20 mm wider. Check rubbing at full lock.
- Shorter sidewall: 0.5 in less.
Cars with 235/60R17
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