245/65 R18 vs 31x10.50 R15
245/65 R18 vs 31x10.50 R15
31x10.50 R15 stays within the configured tolerance for 245/65 R18: +1.5% diameter and +1.5% speedometer effect.
Fitment verdict
31x10.50 R15 stays within the configured tolerance for 245/65 R18: +1.5% diameter and +1.5% speedometer effect.
| Metric | This size: 245/65 R18 | Alternative: 31x10.50 R15 | Difference | Verdict |
|---|---|---|---|---|
| Overall diameter | 30.54 in | 31.00 in | +1.5% | Within tolerance |
| Section width | 9.65 in | 10.50 in | +0.85 in | Computed difference |
| Sidewall height | 6.27 in | 8.00 in | +1.73 in | Computed difference |
| Circumference | 95.94 in | 97.39 in | +1.5% | Within tolerance |
| Speedo | 0.0% | +1.5% | +1.5% | Within tolerance |
Compare sizes
Looks valid
Looks valid
Units
✓ Within toleranceDiameter +1.5% (+0.46 in) · US (~3%)
- Within tolerance · Diameter +1.5%.
- Speedo @ 60: 60 mph → 60.9 mph.
- Sidewall +1.73 in · Width +0.85 in.
Diameter+1.5%+0.46 in
Speedo @ 60+1.5%60 mph → 60.9 mph
Sidewall+1.73 inWidth +0.85 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
- 30.54 in 31.00 in+0.46 in
- Sidewall
- 6.27 in 8.00 in+1.73 in
- Width
- 9.65 in 10.50 in+0.85 in
- Circumference
- 95.94 in 97.39 in+1.5%
- Revs / mile
- 660 651
- Speedo @ 60
- 60 mph 60.9 mph+1.5%
- Current —
245/65 R18 - New —
31x10.50 R15 - Grounded to the road: the axle rises +0.23 in.
Result report
245/65 R18 31x10.50 R15 · Within tolerance
Use this size when shopping: 31x10.50 R15
Geometric estimate. Always verify physical clearance (arches, suspension, brakes) before fitting.
Safe alternative sizes
| Size | Diameter | Speedo @ 100 | Use this |
|---|---|---|---|
−1″ 215/80R17 | +0.0% | +0.0% | |
OE 245/65R18 | +0.0% | +0.0% | |
+1″ 195/75R19 | -0.1% | -0.1% | |
+2″ 335/40R20 | +0.0% | +0.0% |
245/65 R18 · 31x10.50 R15 · Methodology
What changed
- Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.