215/45R17 vs 205/40R18 tire size
205/40R18 vs 215/45R17, diameter
-0.7% shorter
- Speedometer
- 60.4 mph
- At a true 60 mph
- Diameter
- 24.46 in
- Was 24.62 in
- Revs per mile
- 825
- Was 819
- 3% guideline
- Within
Car built for 215/45R17, now on 205/40R18.
215/45R17 and 205/40R18
| Measure | 215/45R17 | 205/40R18 | Difference |
|---|---|---|---|
| Width, mm | 215 | 205 | -10 |
| Sidewall, % of width | 45 | 40 | -5 |
| Rim, in | 17 | 18 | +1 |
| Section height, in | 3.81 | 3.23 | -0.58 |
| Diameter, in | 24.62 | 24.46 | -0.16 (-0.7%) |
| Circumference, in | 77.3 | 76.8 | -0.5 |
| Revs per mile | 819 | 825 | +5 (+0.7%) |
Fitting 205/40R18 instead of 215/45R17
Within the usual 3% diameter guideline.
- Needs 18 in wheels.
- Shorter sidewall: 0.6 in less.
Cars with 215/45R17
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