Comparison
245/45 R20 vs 275/35 R20
Going from 245/45 R20 to 275/35 R20 keeps the rim but tightens the sidewall for a sportier look. This sizing approach swings rolling diameter far enough to feel on the road. Less sidewall flex usually translates to crisper turn-in and a slightly stiffer ride over rough pavement.
The speedometer error is noticeable and may warrant a recalibration if you rely on indicated speed. The 3–5% diameter gap puts this in caution territory: doable on many cars, but verify clearance and consider recalibration.
TakeSuits drivers who value sharper steering and appearance over outright ride softness.
Quick math: 275/35 R20 is 28.0 mm shorter than 245/45 R20, shifting the speedometer by -3.84%.
Current Tire
New Tire
Ground line · scaled comparison
Slight Difference
Within ±5% — usable, recalibration recommended
Diameter change
-28.0 mm
-3.84%
Speedometer at 100
96.2 km/h
-3.84% error
Ground clearance
-14.0 mm
ride height delta
Sidewall change
-14.0 mm
revs/km: 454.4
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/compare/245-45-r20-vs-275-35-r20Detailed comparison
| Metric | 245/45 R20 | 275/35 R20 | Difference |
|---|---|---|---|
| Overall diameter | 728.5 mm | 700.5 mm | -28.0 mm (-3.84%) |
| Sidewall height | 110.3 mm | 96.3 mm | -14.0 mm |
| Circumference | 2.289 m | 2.201 m | -88.0 mm |
| Revs / km | 436.9 | 454.4 | +17.5 |
| Ground clearance | reference | -14.0 mm | -14.0 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 96.2 km/h | -3.84 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 96.2 km/h after switching to 275/35 R20 — a -3.84% 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 -14.0 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.
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245/45 R20
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275/35 R20
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