315/70R17 vs 325/65R18 tire size
325/65R18 vs 315/70R17, diameter
+0.8% taller
- Speedometer
- 59.5 mph
- At a true 60 mph
- Diameter
- 34.63 in
- Was 34.36 in
- Revs per mile
- 582
- Was 587
- 3% guideline
- Within
Car built for 315/70R17, now on 325/65R18.
315/70R17 and 325/65R18
| Measure | 315/70R17 | 325/65R18 | Difference |
|---|---|---|---|
| Width, mm | 315 | 325 | +10 |
| Sidewall, % of width | 70 | 65 | -5 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 8.68 | 8.32 | -0.36 |
| Diameter, in | 34.36 | 34.63 | +0.27 (+0.8%) |
| Circumference, in | 108.0 | 108.8 | +0.9 |
| Revs per mile | 587 | 582 | -5 (-0.8%) |
Fitting 325/65R18 instead of 315/70R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
Cars with 315/70R17
Cars with 325/65R18
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