Comparison
225/55 R17 vs 215/40 R18
Compared to 225/55 R17, 215/40 R18 is 50.1 mm shorter and changes the speedometer reading by -7.38%.
Current Tire
225/55R17
New Tire
215/40R18
225/55 R17
215/40 R18
Ground line · scaled comparison
Not Recommended
Over 5% — speedometer & ABS may misread
Diameter change
-50.1 mm
-7.38%
Speedometer at 100
92.6 km/h
-7.38% error
Ground clearance
-25.0 mm
ride height delta
Sidewall change
-37.8 mm
revs/km: 505.9
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/compare/225-55-r17-vs-215-40-r18Detailed comparison
| Metric | 225/55 R17 | 215/40 R18 | Difference |
|---|---|---|---|
| Overall diameter | 679.3 mm | 629.2 mm | -50.1 mm (-7.38%) |
| Sidewall height | 123.8 mm | 86.0 mm | -37.8 mm |
| Circumference | 2.134 m | 1.977 m | -157.4 mm |
| Revs / km | 468.6 | 505.9 | +37.3 |
| Ground clearance | reference | -25.0 mm | -25.0 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 92.6 km/h | -7.38 km/h |
Verdict: danger
Over 5% diameter difference — likely to affect speedometer accuracy, ABS calibration and gearing. Not recommended without professional review.
Back to
225/55 R17
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215/40 R18