Comparison
285/30 R20 vs 225/45 R17
Compared to 285/30 R20, 225/45 R17 is 44.7 mm shorter and changes the speedometer reading by -6.58%.
Current Tire
285/30R20
New Tire
225/45R17
285/30 R20
225/45 R17
Ground line · scaled comparison
Not Recommended
Over 5% — speedometer & ABS may misread
Diameter change
-44.7 mm
-6.58%
Speedometer at 100
93.4 km/h
-6.58% error
Ground clearance
-22.4 mm
ride height delta
Sidewall change
+15.8 mm
revs/km: 501.8
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/compare/285-30-r20-vs-225-45-r17Detailed comparison
| Metric | 285/30 R20 | 225/45 R17 | Difference |
|---|---|---|---|
| Overall diameter | 679.0 mm | 634.3 mm | -44.7 mm (-6.58%) |
| Sidewall height | 85.5 mm | 101.3 mm | +15.8 mm |
| Circumference | 2.133 m | 1.993 m | -140.4 mm |
| Revs / km | 468.8 | 501.8 | +33.0 |
| Ground clearance | reference | -22.4 mm | -22.4 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 93.4 km/h | -6.58 km/h |
Verdict: danger
Over 5% diameter difference — likely to affect speedometer accuracy, ABS calibration and gearing. Not recommended without professional review.
Back to
285/30 R20
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225/45 R17