Comparison
225/55 R16 vs 255/35 R18
Going from 225/55 R16 to 255/35 R18 steps up to a 18-inch rim while trimming sidewall to stay near OEM rolling diameter. This swap shifts overall diameter slightly from OEM.
The speedometer offset is small but measurable; worth keeping in mind if you watch the dash closely. Expect a more planted steering feel, at the cost of some of the cushioning a taller sidewall provides. More tread on the ground tends to improve dry grip and stance, with a small fuel-economy and clearance tradeoff. Visually, the bigger wheel fills the arch and gives the car a more aggressive stance. Diameter change stays inside the conservative ±3% safety window — an OEM-safe fitment on most vehicles.
TakeA solid pick for drivers chasing a more aggressive stance without abandoning OEM rolling diameter.
Quick math: 255/35 R18 is 18.2 mm shorter than 225/55 R16, shifting the speedometer by -2.78%.
Current Tire
New Tire
Ground line · scaled comparison
Excellent Fit
Within ±3% — safe for daily driving
Diameter change
-18.2 mm
-2.78%
Speedometer at 100
97.2 km/h
-2.78% error
Ground clearance
-9.1 mm
ride height delta
Sidewall change
-34.5 mm
revs/km: 500.7
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/compare/225-55-r16-vs-255-35-r18Detailed comparison
| Metric | 225/55 R16 | 255/35 R18 | Difference |
|---|---|---|---|
| Overall diameter | 653.9 mm | 635.7 mm | -18.2 mm (-2.78%) |
| Sidewall height | 123.8 mm | 89.3 mm | -34.5 mm |
| Circumference | 2.054 m | 1.997 m | -57.2 mm |
| Revs / km | 486.8 | 500.7 | +13.9 |
| Ground clearance | reference | -9.1 mm | -9.1 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 97.2 km/h | -2.78 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 97.2 km/h after switching to 255/35 R18 — a -2.78% 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 -9.1 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
225/55 R16
Back to
255/35 R18
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