Comparison
215/55 R16 vs 225/45 R18
Plus-sizing from 215/55 R16 to 225/45 R18 keeps overall diameter close to factory while opening room for a larger 18-inch wheel. This sizing approach moves rolling diameter a touch off the original spec. Less sidewall flex usually translates to crisper turn-in and a slightly stiffer ride over rough pavement.
Expect a slight but noticeable shift in indicated speed compared to the original tires. 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: 225/45 R18 is 16.8 mm taller than 215/55 R16, shifting the speedometer by +2.61%.
Current Tire
New Tire
Ground line · scaled comparison
Excellent Fit
Within ±3% — safe for daily driving
Diameter change
+16.8 mm
2.61%
Speedometer at 100
102.6 km/h
+2.61% error
Ground clearance
+8.4 mm
ride height delta
Sidewall change
-17.0 mm
revs/km: 482.5
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/compare/215-55-r16-vs-225-45-r18Detailed comparison
| Metric | 215/55 R16 | 225/45 R18 | Difference |
|---|---|---|---|
| Overall diameter | 642.9 mm | 659.7 mm | +16.8 mm (+2.61%) |
| Sidewall height | 118.3 mm | 101.3 mm | -17.0 mm |
| Circumference | 2.020 m | 2.073 m | +52.8 mm |
| Revs / km | 495.1 | 482.5 | -12.6 |
| Ground clearance | reference | +8.4 mm | +8.4 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 102.6 km/h | +2.61 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 102.6 km/h after switching to 225/45 R18 — a +2.61% 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 +8.4 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
215/55 R16
Back to
225/45 R18
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