215/65R17 vs 235/55R18 tire size
235/55R18 vs 215/65R17, diameter
+0.6% taller
- Speedometer
- 59.6 mph
- At a true 60 mph
- Diameter
- 28.18 in
- Was 28.00 in
- Revs per mile
- 716
- Was 720
- 3% guideline
- Within
Car built for 215/65R17, now on 235/55R18.
215/65R17 and 235/55R18
| Measure | 215/65R17 | 235/55R18 | Difference |
|---|---|---|---|
| Width, mm | 215 | 235 | +20 |
| Sidewall, % of width | 65 | 55 | -10 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 5.50 | 5.09 | -0.41 |
| Diameter, in | 28.00 | 28.18 | +0.17 (+0.6%) |
| Circumference, in | 88.0 | 88.5 | +0.5 |
| Revs per mile | 720 | 716 | -4 (-0.6%) |
Fitting 235/55R18 instead of 215/65R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
- 20 mm wider. Check rubbing at full lock.
Cars with 215/65R17
Cars with 235/55R18
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