225/40R18 vs 295/30R18 tire size
295/30R18 vs 225/40R18, diameter
-0.5% shorter
- Speedometer
- 60.3 mph
- At a true 60 mph
- Diameter
- 24.97 in
- Was 25.09 in
- Revs per mile
- 808
- Was 804
- 3% guideline
- Within
Car built for 225/40R18, now on 295/30R18.
225/40R18 and 295/30R18
| Measure | 225/40R18 | 295/30R18 | Difference |
|---|---|---|---|
| Width, mm | 225 | 295 | +70 |
| Sidewall, % of width | 40 | 30 | -10 |
| Rim, in | 18 | 18 | 0 |
| Section height, in | 3.54 | 3.48 | -0.06 |
| Diameter, in | 25.09 | 24.97 | -0.12 (-0.5%) |
| Circumference, in | 78.8 | 78.4 | -0.4 |
| Revs per mile | 804 | 808 | +4 (+0.5%) |
Fitting 295/30R18 instead of 225/40R18
Within the usual 3% diameter guideline.
- 70 mm wider. Check rubbing at full lock.
Cars with 225/40R18
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