33x12.50 R18 vs 275/70 R18
33x12.50 R18 vs 275/70 R18
275/70 R18 stays within the configured tolerance for 33x12.50 R18: +0.5% diameter and +0.5% speedometer effect.
Geometric comparison
275/70 R18 stays within the configured tolerance for 33x12.50 R18: +0.5% diameter and +0.5% speedometer effect.
| Metric | This size: 33x12.50 R18 | Alternative: 275/70 R18 | Difference | Verdict |
|---|---|---|---|---|
| Overall diameter | 33.00 in | 33.16 in | +0.5% | Within tolerance |
| Section width | 12.50 in | 10.83 in | -1.67 in | Computed difference |
| Sidewall height | 7.50 in | 7.58 in | +0.08 in | Computed difference |
| Circumference | 103.67 in | 104.17 in | +0.5% | Within tolerance |
| Speedo | 0.0% | +0.5% | +0.5% | Within tolerance |
Compare sizes
Looks valid
Looks valid
Units
High fitment riskWithin tolerance · Diameter +0.5% (+0.16 in) · US (~3%)
- High fitment risk · This rating covers tire geometry only, not vehicle compatibility.
- Diameter +0.5% · Ride-height change +0.08 in.
- Speedometer reads low · 60 mph → 60.3 mph.
- Sidewall +0.08 in · Width -1.67 in.
Diameter+0.5%+0.16 in
Speedo @ 60+0.5%60 mph → 60.3 mph
Sidewall+0.08 inWidth -1.67 in
Ride-height change+0.08 inDiameter ÷ 2
How this result is calculated
Computed from nominal tire-size geometry: diameter, circumference and speedometer error. It does not check vehicle placard approval, load/speed rating, rim-width range, wheel-arch, suspension or brake clearance.
MethodologyBefore fitting
- Check the vehicle placard and owner’s manual first.
- Match or exceed the required load index and speed rating.
- Confirm rim-width range, bolt pattern, hub bore, offset and fasteners.
- Inspect wheel-arch, suspension and brake clearance under real vehicle load.
- Check TPMS, cold pressure and local roadworthiness rules.
- Diameter
- 33.00 in 33.16 in+0.16 in
- Sidewall
- 7.50 in 7.58 in+0.08 in
- Width
- 12.50 in 10.83 in-1.67 in
- Circumference
- 103.67 in 104.17 in+0.5%
- Revs / mile
- 611 608
- Speedo @ 60
- 60 mph 60.3 mph+0.5%
- Ride-height change
- 0.00 in +0.08 in
- True distance per 100 indicated
- 100 mi 100.5 mi+0.5%
- Current —
33x12.50 R18 - New —
275/70 R18 - Grounded to the road: the axle rises +0.08 in.
Result report
33x12.50 R18 275/70 R18 · High fitment risk · Within tolerance
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Geometric estimate. Always verify physical clearance (arches, suspension, brakes) before fitting.
In-tolerance alternative sizes
| Size | Diameter | Speedo @ 100 | Use this |
|---|---|---|---|
OE 345/55R18 | -0.2% | -0.2% | |
+1″ 355/50R19 | -0.1% | -0.1% |
33x12.50 R18 · 275/70 R18 · Methodology
- Technical check
- 2026-06-28
What changed
- Checked generated routes, metadata, sitemap inclusion and localized page rendering.