255/50R17 vs 215/55R18 tire size
215/55R18 vs 255/50R17, diameter
+1.0% taller
- Speedometer
- 59.4 mph
- At a true 60 mph
- Diameter
- 27.31 in
- Was 27.04 in
- Revs per mile
- 738
- Was 746
- 3% guideline
- Within
Car built for 255/50R17, now on 215/55R18.
255/50R17 and 215/55R18
| Measure | 255/50R17 | 215/55R18 | Difference |
|---|---|---|---|
| Width, mm | 255 | 215 | -40 |
| Sidewall, % of width | 50 | 55 | +5 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 5.02 | 4.66 | -0.36 |
| Diameter, in | 27.04 | 27.31 | +0.27 (+1.0%) |
| Circumference, in | 84.9 | 85.8 | +0.9 |
| Revs per mile | 746 | 738 | -7 (-1.0%) |
Fitting 215/55R18 instead of 255/50R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
Cars with 255/50R17
Cars with 215/55R18
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