Comparison
265/40 R21 vs 285/35 R21
Stepping from 265/40 R21 to 285/35 R21 keeps the 21-inch wheel but widens the section by 20 mm. This swap shifts overall diameter slightly from OEM. Expect a more planted steering feel, at the cost of some of the cushioning a taller sidewall provides.
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.
TakeUseful when extra dry grip and stance matter more than a small fuel-economy hit.
Quick math: 285/35 R21 is 12.5 mm shorter than 265/40 R21, shifting the speedometer by -1.68%.
Current Tire
New Tire
Ground line · scaled comparison
Excellent Fit
Within ±3% — safe for daily driving
Diameter change
-12.5 mm
-1.68%
Speedometer at 100
98.3 km/h
-1.68% error
Ground clearance
-6.3 mm
ride height delta
Sidewall change
-6.3 mm
revs/km: 434.3
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/compare/265-40-r21-vs-285-35-r21Detailed comparison
| Metric | 265/40 R21 | 285/35 R21 | Difference |
|---|---|---|---|
| Overall diameter | 745.4 mm | 732.9 mm | -12.5 mm (-1.68%) |
| Sidewall height | 106.0 mm | 99.8 mm | -6.3 mm |
| Circumference | 2.342 m | 2.302 m | -39.3 mm |
| Revs / km | 427.0 | 434.3 | +7.3 |
| Ground clearance | reference | -6.3 mm | -6.3 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 98.3 km/h | -1.68 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 98.3 km/h after switching to 285/35 R21 — a -1.68% 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 -6.3 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
265/40 R21
Back to
285/35 R21
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