255/35 R20 vs 255/40 R19

255/35 R20 vs 255/40 R19

255/40 R19 stays within the configured tolerance for 255/35 R20: 0.0% diameter and 0.0% speedometer effect.

Fitment verdict

255/40 R19 stays within the configured tolerance for 255/35 R20: 0.0% diameter and 0.0% speedometer effect.

Metric This size: 255/35 R20 Alternative: 255/40 R19 Difference Verdict
Overall diameter 27.03 in 27.03 in 0.0% Within tolerance
Section width 10.04 in 10.04 in 0.00 in Computed difference
Sidewall height 3.51 in 4.02 in +0.50 in Computed difference
Circumference 84.91 in 84.92 in 0.0% Within tolerance
Speedo 0.0% 0.0% 0.0% Within tolerance

Compare sizes

Looks valid
Looks valid
Units
✓ Within toleranceDiameter +0.0% (+0.00 in) · US (~3%)
  • Within tolerance · Diameter +0.0%.
  • Speedo @ 60: 60 mph60.0 mph.
  • Sidewall +0.50 in · Width +0.00 in.
Diameter+0.0%+0.00 in
Speedo @ 60+0.0%60 mph60.0 mph
Sidewall+0.50 inWidth +0.00 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
27.03 in 27.03 in+0.00 in
Sidewall
3.51 in 4.02 in+0.50 in
Width
10.04 in 10.04 in+0.00 in
Circumference
84.91 in 84.92 in+0.0%
Revs / mile
746 746
Speedo @ 60
60 mph 60.0 mph+0.0%
Δ⌀ +0.1 mm
  • Current255/35 R20
  • New255/40 R19
  • Grounded to the road: the axle rises +0.00 in.

Result report

255/35 R20 255/40 R19 · Within tolerance

Use this size when shopping: 255/40 R19

Use this size when shopping

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

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 255/40R19+0.0%+0.0%
OE 255/35R20+0.0%+0.0%
+1″ 255/30R21-0.0%-0.0%
+2″ 255/25R22-0.0%-0.0%

255/35 R20 · 255/40 R19 · Methodology

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