Comparison
215/55 R17 vs 255/40 R17
255/40 R17 is a lower-profile take on 215/55 R17 — same 17-inch wheel, shorter sidewall. This wheel and tire pairing swings rolling diameter far enough to feel on the road.
The speedometer error is noticeable and may warrant a recalibration if you rely on indicated speed. The shorter sidewall gives the tire a firmer, more responsive feel and sharpens steering input. The wider section adds contact patch and lateral stability, while eating into fender and suspension clearance. The 3–5% diameter gap puts this in caution territory: doable on many cars, but verify clearance and consider recalibration.
TakeSuits drivers who value sharper steering and appearance over outright ride softness.
Quick math: 255/40 R17 is 32.5 mm shorter than 215/55 R17, shifting the speedometer by -4.86%.
Current Tire
New Tire
Ground line · scaled comparison
Slight Difference
Within ±5% — usable, recalibration recommended
Diameter change
-32.5 mm
-4.86%
Speedometer at 100
95.1 km/h
-4.86% error
Ground clearance
-16.3 mm
ride height delta
Sidewall change
-16.3 mm
revs/km: 500.6
Permalink for this comparison:
/compare/215-55-r17-vs-255-40-r17Detailed comparison
| Metric | 215/55 R17 | 255/40 R17 | Difference |
|---|---|---|---|
| Overall diameter | 668.3 mm | 635.8 mm | -32.5 mm (-4.86%) |
| Sidewall height | 118.3 mm | 102.0 mm | -16.3 mm |
| Circumference | 2.100 m | 1.997 m | -102.1 mm |
| Revs / km | 476.3 | 500.6 | +24.3 |
| Ground clearance | reference | -16.3 mm | -16.3 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 95.1 km/h | -4.86 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 95.1 km/h after switching to 255/40 R17 — a -4.86% 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 -16.3 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 R17
Back to
255/40 R17
Drivers also compare
Closely-related fitments and plus-size swaps for 215/55 R17 and 255/40 R17.
205/50 R17 vs 255/40 R17
Wider variation on the same rim — more grip, less clearance.
Δ 0.16%
225/45 R17 vs 255/40 R17
Wider variation on the same rim — more grip, less clearance.
Δ 0.24%
235/45 R17 vs 255/40 R17
Wider variation on the same rim — more grip, less clearance.
Δ 1.17%
245/40 R17 vs 255/40 R17
Wider variation on the same rim — more grip, less clearance.
Δ 1.27%
215/55 R17 vs 225/55 R17
Wider variation on the same rim — more grip, less clearance.
Δ 1.65%
215/45 R17 vs 255/40 R17
Wider variation on the same rim — more grip, less clearance.
Δ 1.68%
215/50 R17 vs 255/40 R17
Wider variation on the same rim — more grip, less clearance.
Δ 1.70%
215/55 R17 vs 225/50 R17
Wider variation on the same rim — more grip, less clearance.
Δ 1.72%
Related topics