Comparison
245/40 R20 vs 285/35 R19
Going from 245/40 R20 to 285/35 R19 is a minus-1 setup that adds sidewall on a smaller 19-inch wheel. This alternative fitment noticeably changes overall diameter compared to OEM. Expect a more planted steering feel, at the cost of some of the cushioning a taller sidewall provides.
The speedometer error is noticeable and may warrant a recalibration if you rely on indicated speed. Diameter delta falls in the cautious 3–5% range, where speedometer recalibration and a careful clearance check are worth doing.
TakePractical direction for winter wheels, chains, or rougher pavement where cushioning matters.
Quick math: 285/35 R19 is 21.9 mm shorter than 245/40 R20, shifting the speedometer by -3.11%.
Current Tire
New Tire
Ground line · scaled comparison
Slight Difference
Within ±5% — usable, recalibration recommended
Diameter change
-21.9 mm
-3.11%
Speedometer at 100
96.9 km/h
-3.11% error
Ground clearance
-11.0 mm
ride height delta
Sidewall change
+1.8 mm
revs/km: 466.7
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/compare/245-40-r20-vs-285-35-r19Detailed comparison
| Metric | 245/40 R20 | 285/35 R19 | Difference |
|---|---|---|---|
| Overall diameter | 704.0 mm | 682.1 mm | -21.9 mm (-3.11%) |
| Sidewall height | 98.0 mm | 99.8 mm | +1.8 mm |
| Circumference | 2.212 m | 2.143 m | -68.8 mm |
| Revs / km | 452.1 | 466.7 | +14.5 |
| Ground clearance | reference | -11.0 mm | -11.0 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 96.9 km/h | -3.11 km/h |
Verdict: warning
Between 3% and 5% — noticeable speedometer drift; recalibration may be advisable.
Speedometer impact
At a true 100 km/h, your dashboard will read 96.9 km/h after switching to 285/35 R19 — a -3.11% offset. Use the speedometer error calculator to recheck for other indicated speeds, and the speedometer error guide for the full background.
Ground clearance change
The new tire's half-diameter changes ride height by -11.0 mm. Small differences are absorbed by suspension travel, but anything beyond ±10 mm can affect headlight aim, fender clearance and bump-stop margin. See the plus-sizing guide before committing.
Back to
245/40 R20
Back to
285/35 R19
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