215/70R17 vs 245/55R18 tire size
245/55R18 vs 215/70R17, diameter
-0.8% shorter
- Speedometer
- 60.5 mph
- At a true 60 mph
- Diameter
- 28.61 in
- Was 28.85 in
- Revs per mile
- 705
- Was 699
- 3% guideline
- Within
Car built for 215/70R17, now on 245/55R18.
215/70R17 and 245/55R18
| Measure | 215/70R17 | 245/55R18 | Difference |
|---|---|---|---|
| Width, mm | 215 | 245 | +30 |
| Sidewall, % of width | 70 | 55 | -15 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 5.93 | 5.31 | -0.62 |
| Diameter, in | 28.85 | 28.61 | -0.24 (-0.8%) |
| Circumference, in | 90.6 | 89.9 | -0.8 |
| Revs per mile | 699 | 705 | +6 (+0.8%) |
Fitting 245/55R18 instead of 215/70R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
- 30 mm wider. Check rubbing at full lock.
- Shorter sidewall: 0.6 in less.
Cars with 245/55R18
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