31x10.50 R15 vs 305/40 R22

31x10.50 R15 vs 305/40 R22

305/40 R22 stays within the configured tolerance for 31x10.50 R15: +2.0% diameter and +2.0% speedometer effect.

Fitment verdict

305/40 R22 stays within the configured tolerance for 31x10.50 R15: +2.0% diameter and +2.0% speedometer effect.

Metric This size: 31x10.50 R15 Alternative: 305/40 R22 Difference Verdict
Overall diameter 31.00 in 31.61 in +2.0% Within tolerance
Section width 10.50 in 12.01 in +1.51 in Computed difference
Sidewall height 8.00 in 4.80 in -3.20 in Computed difference
Circumference 97.39 in 99.29 in +2.0% Within tolerance
Speedo 0.0% +2.0% +2.0% Within tolerance

Compare sizes

Looks valid
Looks valid
Units
✓ Within toleranceDiameter +2.0% (+0.61 in) · US (~3%)
  • Within tolerance · Diameter +2.0%.
  • Speedo @ 60: 60 mph61.2 mph.
  • Sidewall -3.20 in · Width +1.51 in.
Diameter+2.0%+0.61 in
Speedo @ 60+2.0%60 mph61.2 mph
Sidewall-3.20 inWidth +1.51 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
31.00 in 31.61 in+0.61 in
Sidewall
8.00 in 4.80 in-3.20 in
Width
10.50 in 12.01 in+1.51 in
Circumference
97.39 in 99.29 in+2.0%
Revs / mile
651 638
Speedo @ 60
60 mph 61.2 mph+2.0%
Δ⌀ +15.4 mm
  • Current31x10.50 R15
  • New305/40 R22
  • Grounded to the road: the axle rises +0.30 in.

Result report

31x10.50 R15 305/40 R22 · Within tolerance

Use this size when shopping: 305/40 R22

Use this size when shopping

Geometric estimate. Always verify physical clearance (arches, suspension, brakes) before fitting.

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 335/65R14+0.5%+0.5%
OE 255/80R15+0.2%+0.2%
+1″ 345/55R16-0.2%-0.2%
+2″ 355/50R17-0.1%-0.1%

31x10.50 R15 · 305/40 R22 · Methodology

Last reviewed: 2026-06-28
What changed
  • Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.