235/45R18 vs 225/40R19 tire size
225/40R19 vs 235/45R18, diameter
-0.9% shorter
- Speedometer
- 60.6 mph
- At a true 60 mph
- Diameter
- 26.09 in
- Was 26.33 in
- Revs per mile
- 773
- Was 766
- 3% guideline
- Within
Car built for 235/45R18, now on 225/40R19.
235/45R18 and 225/40R19
| Measure | 235/45R18 | 225/40R19 | Difference |
|---|---|---|---|
| Width, mm | 235 | 225 | -10 |
| Sidewall, % of width | 45 | 40 | -5 |
| Rim, in | 18 | 19 | +1 |
| Section height, in | 4.16 | 3.54 | -0.62 |
| Diameter, in | 26.33 | 26.09 | -0.24 (-0.9%) |
| Circumference, in | 82.7 | 82.0 | -0.8 |
| Revs per mile | 766 | 773 | +7 (+0.9%) |
Fitting 225/40R19 instead of 235/45R18
Within the usual 3% diameter guideline.
- Needs 19 in wheels.
- Shorter sidewall: 0.6 in less.
Cars with 235/45R18
Cars with 225/40R19
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