205/55 R16 vs 255/35 R18
205/55 R16 vs 255/35 R18
255/35 R18 stays within the configured tolerance for 205/55 R16: +0.6% diameter and +0.6% speedometer effect.
Fitment verdict
255/35 R18 stays within the configured tolerance for 205/55 R16: +0.6% diameter and +0.6% speedometer effect.
| Metric | This size: 205/55 R16 | Alternative: 255/35 R18 | Difference | Verdict |
|---|---|---|---|---|
| Overall diameter | 24.88 in | 25.03 in | +0.6% | Within tolerance |
| Section width | 8.07 in | 10.04 in | +1.97 in | Computed difference |
| Sidewall height | 4.44 in | 3.51 in | -0.93 in | Computed difference |
| Circumference | 78.16 in | 78.63 in | +0.6% | Within tolerance |
| Speedo | 0.0% | +0.6% | +0.6% | Within tolerance |
Compare sizes
Looks valid
Looks valid
Units
✓ Within toleranceDiameter +0.6% (+0.15 in) · US (~3%)
- Within tolerance · Diameter +0.6%.
- Speedo @ 60: 60 mph → 60.4 mph.
- Sidewall -0.93 in · Width +1.97 in.
Diameter+0.6%+0.15 in
Speedo @ 60+0.6%60 mph → 60.4 mph
Sidewall-0.93 inWidth +1.97 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
- 24.88 in 25.03 in+0.15 in
- Sidewall
- 4.44 in 3.51 in-0.93 in
- Width
- 8.07 in 10.04 in+1.97 in
- Circumference
- 78.16 in 78.63 in+0.6%
- Revs / mile
- 811 806
- Speedo @ 60
- 60 mph 60.4 mph+0.6%
- Current —
205/55 R16 - New —
255/35 R18 - Grounded to the road: the axle rises +0.07 in.
Result report
205/55 R16 255/35 R18 · Within tolerance
Use this size when shopping: 255/35 R18
Geometric estimate. Always verify physical clearance (arches, suspension, brakes) before fitting.
Safe alternative sizes
| Size | Diameter | Speedo @ 100 | Use this |
|---|---|---|---|
−1″ 315/40R15 | +0.2% | +0.2% | |
OE 205/55R16 | +0.0% | +0.0% | |
+1″ 125/80R17 | -0.0% | -0.0% | |
+2″ 125/70R18 | +0.0% | +0.0% |
205/55 R16 · 255/35 R18 · Methodology
What changed
- Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.