Comparison
225/60 R16 vs 255/40 R18
Going from 225/60 R16 to 255/40 R18 steps up to a 18-inch rim while trimming sidewall to stay near OEM rolling diameter. This tire combination moves rolling diameter a touch off the original spec. Expect a slight but noticeable shift in indicated speed compared to the original tires. The shorter sidewall gives the tire a firmer, more responsive feel and sharpens steering input. Overall the swap sits inside the safe ±3% diameter window, so ABS, traction control and gearing behave normally.
TakeCommon upgrade for sportier handling and a tighter wheel-gap look on the same vehicle.
Quick math: 255/40 R18 is 15.2 mm shorter than 225/60 R16, shifting the speedometer by -2.25%.
Current Tire
New Tire
Ground line · scaled comparison
Excellent Fit
Within ±3% — safe for daily driving
Diameter change
-15.2 mm
-2.25%
Speedometer at 100
97.8 km/h
-2.25% error
Ground clearance
-7.6 mm
ride height delta
Sidewall change
-33.0 mm
revs/km: 481.4
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/compare/225-60-r16-vs-255-40-r18Detailed comparison
| Metric | 225/60 R16 | 255/40 R18 | Difference |
|---|---|---|---|
| Overall diameter | 676.4 mm | 661.2 mm | -15.2 mm (-2.25%) |
| Sidewall height | 135.0 mm | 102.0 mm | -33.0 mm |
| Circumference | 2.125 m | 2.077 m | -47.8 mm |
| Revs / km | 470.6 | 481.4 | +10.8 |
| Ground clearance | reference | -7.6 mm | -7.6 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 97.8 km/h | -2.25 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 97.8 km/h after switching to 255/40 R18 — a -2.25% 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 -7.6 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
225/60 R16
Back to
255/40 R18
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