255/45R17 vs 225/45R18 tire size
225/45R18 vs 255/45R17, diameter
-0.2% shorter
- Speedometer
- 60.1 mph
- At a true 60 mph
- Diameter
- 25.97 in
- Was 26.04 in
- Revs per mile
- 777
- Was 775
- 3% guideline
- Within
Car built for 255/45R17, now on 225/45R18.
255/45R17 and 225/45R18
| Measure | 255/45R17 | 225/45R18 | Difference |
|---|---|---|---|
| Width, mm | 255 | 225 | -30 |
| Sidewall, % of width | 45 | 45 | 0 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 4.52 | 3.99 | -0.53 |
| Diameter, in | 26.04 | 25.97 | -0.06 (-0.2%) |
| Circumference, in | 81.8 | 81.6 | -0.2 |
| Revs per mile | 775 | 777 | +2 (+0.2%) |
Fitting 225/45R18 instead of 255/45R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
- Shorter sidewall: 0.5 in less.
Cars with 225/45R18
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