Comparison
225/50 R18 vs 275/40 R18
Going from 225/50 R18 to 275/40 R18 keeps the rim but tightens the sidewall for a sportier look. This setup keeps overall diameter very close to stock. Dashboard speed shifts only marginally — within the noise of normal OEM tolerance. Less sidewall flex usually translates to crisper turn-in and a slightly stiffer ride over rough pavement. Overall the swap sits inside the safe ±3% diameter window, so ABS, traction control and gearing behave normally.
TakeSuits drivers who value sharper steering and appearance over outright ride softness.
Quick math: 275/40 R18 is 5.0 mm shorter than 225/50 R18, shifting the speedometer by -0.73%.
Current Tire
New Tire
Ground line · scaled comparison
Excellent Fit
Within ±3% — safe for daily driving
Diameter change
-5.0 mm
-0.73%
Speedometer at 100
99.3 km/h
-0.73% error
Ground clearance
-2.5 mm
ride height delta
Sidewall change
-2.5 mm
revs/km: 470.0
Permalink for this comparison:
/compare/225-50-r18-vs-275-40-r18Detailed comparison
| Metric | 225/50 R18 | 275/40 R18 | Difference |
|---|---|---|---|
| Overall diameter | 682.2 mm | 677.2 mm | -5.0 mm (-0.73%) |
| Sidewall height | 112.5 mm | 110.0 mm | -2.5 mm |
| Circumference | 2.143 m | 2.127 m | -15.7 mm |
| Revs / km | 466.6 | 470.0 | +3.4 |
| Ground clearance | reference | -2.5 mm | -2.5 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 99.3 km/h | -0.73 km/h |
Verdict: excellent
Within ±3% — speedometer, ABS and traction control should behave normally.
Speedometer impact
At a true 100 km/h, your dashboard will read 99.3 km/h after switching to 275/40 R18 — a -0.73% 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 -2.5 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
225/50 R18
Back to
275/40 R18
Drivers also compare
Closely-related fitments and plus-size swaps for 225/50 R18 and 275/40 R18.
245/45 R18 vs 275/40 R18
Wider variation on the same rim — more grip, less clearance.
Δ 0.07%
225/50 R18 vs 245/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 0.66%
225/50 R18 vs 255/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 0.66%
265/40 R18 vs 275/40 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.20%
235/45 R18 vs 275/40 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.27%
255/45 R18 vs 275/40 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.38%
225/50 R18 vs 235/50 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.47%
225/50 R18 vs 265/40 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.91%
Related topics