Comparison
225/45 R18 vs 245/35 R18
Going from 225/45 R18 to 245/35 R18 keeps the rim but tightens the sidewall for a sportier look. This setup moves rolling diameter well outside the usual OEM tolerance. 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: 245/35 R18 is 31.0 mm shorter than 225/45 R18, shifting the speedometer by -4.70%.
Current Tire
New Tire
Ground line · scaled comparison
Slight Difference
Within ±5% — usable, recalibration recommended
Diameter change
-31.0 mm
-4.70%
Speedometer at 100
95.3 km/h
-4.70% error
Ground clearance
-15.5 mm
ride height delta
Sidewall change
-15.5 mm
revs/km: 506.3
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/compare/225-45-r18-vs-245-35-r18Detailed comparison
| Metric | 225/45 R18 | 245/35 R18 | Difference |
|---|---|---|---|
| Overall diameter | 659.7 mm | 628.7 mm | -31.0 mm (-4.70%) |
| Sidewall height | 101.3 mm | 85.8 mm | -15.5 mm |
| Circumference | 2.073 m | 1.975 m | -97.4 mm |
| Revs / km | 482.5 | 506.3 | +23.8 |
| Ground clearance | reference | -15.5 mm | -15.5 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 95.3 km/h | -4.70 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 95.3 km/h after switching to 245/35 R18 — a -4.70% 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 -15.5 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
225/45 R18
Back to
245/35 R18
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