225/35 R19 vs 235/40 R18

235/40 R18 stays within the configured tolerance for 225/35 R19: +0.8% diameter and +0.8% speedometer effect.

Fitment verdict

235/40 R18 stays within the configured tolerance for 225/35 R19: +0.8% diameter and +0.8% speedometer effect.

Metric	This size: 225/35 R19	Alternative: 235/40 R18	Difference	Verdict
Overall diameter	25.20 in	25.40 in	+0.8%	Within tolerance
Section width	8.86 in	9.25 in	+0.39 in	Computed difference
Sidewall height	3.10 in	3.70 in	+0.60 in	Computed difference
Circumference	79.17 in	79.80 in	+0.8%	Within tolerance
Speedo	0.0%	+0.8%	+0.8%	Within tolerance

Current tireLooks valid

New tireLooks valid

Market

Units

✓ Within toleranceDiameter +0.8% (+0.20 in) · US (~3%)

Diameter+0.8%+0.20 in

Speedo @ 60+0.8%60 mph → 60.5 mph

Sidewall+0.60 inWidth +0.39 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.

225/35 R19 235/40 R18 · Within tolerance

Use this size when shopping: 235/40 R18

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

Size	Diameter	Speedo @ 100
−1″ `305/30R18`	+0.0%	+0.0%
OE `225/35R19`	+0.0%	+0.0%
+1″ `165/40R20`	-0.0%	-0.0%
+2″ `215/25R21`	+0.1%	+0.1%

What changed

Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.