245/45R18 vs 245/40R19 tire size
245/40R19 vs 245/45R18, diameter
+0.1% taller
- Speedometer
- 59.9 mph
- At a true 60 mph
- Diameter
- 26.72 in
- Was 26.68 in
- Revs per mile
- 755
- Was 756
- 3% guideline
- Within
Car built for 245/45R18, now on 245/40R19.
245/45R18 and 245/40R19
| Measure | 245/45R18 | 245/40R19 | Difference |
|---|---|---|---|
| Width, mm | 245 | 245 | 0 |
| Sidewall, % of width | 45 | 40 | -5 |
| Rim, in | 18 | 19 | +1 |
| Section height, in | 4.34 | 3.86 | -0.48 |
| Diameter, in | 26.68 | 26.72 | +0.04 (+0.1%) |
| Circumference, in | 83.8 | 83.9 | +0.1 |
| Revs per mile | 756 | 755 | -1 (-0.1%) |
Fitting 245/40R19 instead of 245/45R18
Within the usual 3% diameter guideline.
- Needs 19 in wheels.
Cars with 245/45R18
Cars with 245/40R19
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