Comparison
225/50 R18 vs 255/40 R19
Going from 225/50 R18 to 255/40 R19 steps up to a 19-inch rim while trimming sidewall to stay near OEM rolling diameter. This swap lands within OEM rolling-diameter tolerance. Dashboard speed shifts only marginally — within the noise of normal OEM tolerance. Expect a more planted steering feel, at the cost of some of the cushioning a taller sidewall provides. Diameter change stays inside the conservative ±3% safety window — an OEM-safe fitment on most vehicles.
TakeCommon upgrade for sportier handling and a tighter wheel-gap look on the same vehicle.
Quick math: 255/40 R19 is 4.4 mm taller than 225/50 R18, shifting the speedometer by +0.64%.
Current Tire
New Tire
Ground line · scaled comparison
Excellent Fit
Within ±3% — safe for daily driving
Diameter change
+4.4 mm
0.64%
Speedometer at 100
100.6 km/h
+0.64% error
Ground clearance
+2.2 mm
ride height delta
Sidewall change
-10.5 mm
revs/km: 463.6
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/compare/225-50-r18-vs-255-40-r19Detailed comparison
| Metric | 225/50 R18 | 255/40 R19 | Difference |
|---|---|---|---|
| Overall diameter | 682.2 mm | 686.6 mm | +4.4 mm (+0.64%) |
| Sidewall height | 112.5 mm | 102.0 mm | -10.5 mm |
| Circumference | 2.143 m | 2.157 m | +13.8 mm |
| Revs / km | 466.6 | 463.6 | -3.0 |
| Ground clearance | reference | +2.2 mm | +2.2 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 100.6 km/h | +0.64 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 100.6 km/h after switching to 255/40 R19 — a +0.64% 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 +2.2 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
255/40 R19
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