245/40R18 vs 275/35R18 tire size
275/35R18 vs 245/40R18, diameter
-0.5% shorter
- Speedometer
- 60.3 mph
- At a true 60 mph
- Diameter
- 25.58 in
- Was 25.72 in
- Revs per mile
- 788
- Was 784
- 3% guideline
- Within
Car built for 245/40R18, now on 275/35R18.
245/40R18 and 275/35R18
| Measure | 245/40R18 | 275/35R18 | Difference |
|---|---|---|---|
| Width, mm | 245 | 275 | +30 |
| Sidewall, % of width | 40 | 35 | -5 |
| Rim, in | 18 | 18 | 0 |
| Section height, in | 3.86 | 3.79 | -0.07 |
| Diameter, in | 25.72 | 25.58 | -0.14 (-0.5%) |
| Circumference, in | 80.8 | 80.4 | -0.4 |
| Revs per mile | 784 | 788 | +4 (+0.5%) |
Fitting 275/35R18 instead of 245/40R18
Within the usual 3% diameter guideline.
- 30 mm wider. Check rubbing at full lock.
Cars with 245/40R18
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