Comparison
255/45 R18 vs 255/45 R19
Plus-sizing from 255/45 R18 to 255/45 R19 keeps overall diameter close to factory while opening room for a larger 19-inch wheel. This setup moves rolling diameter well outside the usual OEM tolerance. Many drivers pick this direction primarily for appearance — the bigger rim simply looks more aggressive.
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.
TakeCommon upgrade for sportier handling and a tighter wheel-gap look on the same vehicle.
Quick math: 255/45 R19 is 25.4 mm taller than 255/45 R18, shifting the speedometer by +3.70%.
Current Tire
New Tire
Ground line · scaled comparison
Slight Difference
Within ±5% — usable, recalibration recommended
Diameter change
+25.4 mm
3.70%
Speedometer at 100
103.7 km/h
+3.70% error
Ground clearance
+12.7 mm
ride height delta
Sidewall change
0.0 mm
revs/km: 447.0
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/compare/255-45-r18-vs-255-45-r19Detailed comparison
| Metric | 255/45 R18 | 255/45 R19 | Difference |
|---|---|---|---|
| Overall diameter | 686.7 mm | 712.1 mm | +25.4 mm (+3.70%) |
| Sidewall height | 114.8 mm | 114.8 mm | 0.0 mm |
| Circumference | 2.157 m | 2.237 m | +79.8 mm |
| Revs / km | 463.5 | 447.0 | -16.5 |
| Ground clearance | reference | +12.7 mm | +12.7 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 103.7 km/h | +3.70 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 103.7 km/h after switching to 255/45 R19 — a +3.70% 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 +12.7 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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255/45 R18
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255/45 R19
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