225/50R18 vs 245/45R18 tire size
245/45R18 vs 225/50R18, diameter
-0.7% shorter
- Speedometer
- 60.4 mph
- At a true 60 mph
- Diameter
- 26.68 in
- Was 26.86 in
- Revs per mile
- 756
- Was 751
- 3% guideline
- Within
Car built for 225/50R18, now on 245/45R18.
225/50R18 and 245/45R18
| Measure | 225/50R18 | 245/45R18 | Difference |
|---|---|---|---|
| Width, mm | 225 | 245 | +20 |
| Sidewall, % of width | 50 | 45 | -5 |
| Rim, in | 18 | 18 | 0 |
| Section height, in | 4.43 | 4.34 | -0.09 |
| Diameter, in | 26.86 | 26.68 | -0.18 (-0.7%) |
| Circumference, in | 84.4 | 83.8 | -0.6 |
| Revs per mile | 751 | 756 | +5 (+0.7%) |
Fitting 245/45R18 instead of 225/50R18
Within the usual 3% diameter guideline.
- 20 mm wider. Check rubbing at full lock.
Cars with 225/50R18
Cars with 245/45R18
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