215/40R18 vs 255/35R18 tire size
255/35R18 vs 215/40R18, diameter
+1.0% taller
- Speedometer
- 59.4 mph
- At a true 60 mph
- Diameter
- 25.03 in
- Was 24.77 in
- Revs per mile
- 806
- Was 814
- 3% guideline
- Within
Car built for 215/40R18, now on 255/35R18.
215/40R18 and 255/35R18
| Measure | 215/40R18 | 255/35R18 | Difference |
|---|---|---|---|
| Width, mm | 215 | 255 | +40 |
| Sidewall, % of width | 40 | 35 | -5 |
| Rim, in | 18 | 18 | 0 |
| Section height, in | 3.39 | 3.51 | +0.13 |
| Diameter, in | 24.77 | 25.03 | +0.26 (+1.0%) |
| Circumference, in | 77.8 | 78.6 | +0.8 |
| Revs per mile | 814 | 806 | -8 (-1.0%) |
Fitting 255/35R18 instead of 215/40R18
Within the usual 3% diameter guideline.
- 40 mm wider. Check rubbing at full lock.
Cars with 215/40R18
Cars with 255/35R18
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