255/35 R18 vs 225/40 R18
255/35 R18 vs 225/40 R18
225/40 R18 stays within the configured tolerance for 255/35 R18: +0.2% diameter and +0.2% speedometer effect.
Fitment verdict
225/40 R18 stays within the configured tolerance for 255/35 R18: +0.2% diameter and +0.2% speedometer effect.
| Metric | This size: 255/35 R18 | Alternative: 225/40 R18 | Difference | Verdict |
|---|---|---|---|---|
| Overall diameter | 25.03 in | 25.09 in | +0.2% | Within tolerance |
| Section width | 10.04 in | 8.86 in | -1.18 in | Computed difference |
| Sidewall height | 3.51 in | 3.54 in | +0.03 in | Computed difference |
| Circumference | 78.63 in | 78.81 in | +0.2% | Within tolerance |
| Speedo | 0.0% | +0.2% | +0.2% | Within tolerance |
Compare sizes
Looks valid
Looks valid
Units
✓ Within toleranceDiameter +0.2% (+0.06 in) · US (~3%)
- Within tolerance · Diameter +0.2%.
- Speedo @ 60: 60 mph → 60.1 mph.
- Sidewall +0.03 in · Width -1.18 in.
Diameter+0.2%+0.06 in
Speedo @ 60+0.2%60 mph → 60.1 mph
Sidewall+0.03 inWidth -1.18 in
How this result is calculated
Computed from nominal tire-size geometry: diameter, circumference and speedometer error. It does not check wheel-arch, suspension or brake clearance.
Methodology- Diameter
- 25.03 in 25.09 in+0.06 in
- Sidewall
- 3.51 in 3.54 in+0.03 in
- Width
- 10.04 in 8.86 in-1.18 in
- Circumference
- 78.63 in 78.81 in+0.2%
- Revs / mile
- 806 804
- Speedo @ 60
- 60 mph 60.1 mph+0.2%
- Current —
255/35 R18 - New —
225/40 R18 - Grounded to the road: the axle rises +0.03 in.
Result report
255/35 R18 225/40 R18 · Within tolerance
Use this size when shopping: 225/40 R18
Geometric estimate. Always verify physical clearance (arches, suspension, brakes) before fitting.
Safe alternative sizes
| Size | Diameter | Speedo @ 100 | Use this |
|---|---|---|---|
−1″ 255/40R17 | +0.0% | +0.0% | |
OE 255/35R18 | +0.0% | +0.0% | |
+1″ 255/30R19 | -0.0% | -0.0% | |
+2″ 255/25R20 | -0.0% | -0.0% |
255/35 R18 · 225/40 R18 · Methodology
What changed
- Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.