225/65R17 vs 235/55R18 tire size
235/55R18 vs 225/65R17, diameter
-1.2% shorter
- Speedometer
- 60.7 mph
- At a true 60 mph
- Diameter
- 28.18 in
- Was 28.52 in
- Revs per mile
- 716
- Was 707
- 3% guideline
- Within
Car built for 225/65R17, now on 235/55R18.
225/65R17 and 235/55R18
| Measure | 225/65R17 | 235/55R18 | Difference |
|---|---|---|---|
| Width, mm | 225 | 235 | +10 |
| Sidewall, % of width | 65 | 55 | -10 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 5.76 | 5.09 | -0.67 |
| Diameter, in | 28.52 | 28.18 | -0.34 (-1.2%) |
| Circumference, in | 89.6 | 88.5 | -1.1 |
| Revs per mile | 707 | 716 | +8 (+1.2%) |
Fitting 235/55R18 instead of 225/65R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
- Shorter sidewall: 0.7 in less.
Cars with 225/65R17
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