225/60R17 vs 315/40R18 tire size
315/40R18 vs 225/60R17, diameter
+1.1% taller
- Speedometer
- 59.4 mph
- At a true 60 mph
- Diameter
- 27.92 in
- Was 27.63 in
- Revs per mile
- 722
- Was 730
- 3% guideline
- Within
Car built for 225/60R17, now on 315/40R18.
225/60R17 and 315/40R18
| Measure | 225/60R17 | 315/40R18 | Difference |
|---|---|---|---|
| Width, mm | 225 | 315 | +90 |
| Sidewall, % of width | 60 | 40 | -20 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 5.31 | 4.96 | -0.35 |
| Diameter, in | 27.63 | 27.92 | +0.29 (+1.1%) |
| Circumference, in | 86.8 | 87.7 | +0.9 |
| Revs per mile | 730 | 722 | -8 (-1.0%) |
Fitting 315/40R18 instead of 225/60R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
- 90 mm wider. Check rubbing at full lock.
Cars with 225/60R17
Cars with 315/40R18
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