195/60 R16 vs 235/40 R18

235/40 R18 stays within the configured tolerance for 195/60 R16: +0.7% diameter and +0.7% speedometer effect.

Fitment verdict

235/40 R18 stays within the configured tolerance for 195/60 R16: +0.7% diameter and +0.7% speedometer effect.

Metric	This size: 195/60 R16	Alternative: 235/40 R18	Difference	Verdict
Overall diameter	25.21 in	25.40 in	+0.7%	Within tolerance
Section width	7.68 in	9.25 in	+1.57 in	Computed difference
Sidewall height	4.61 in	3.70 in	-0.91 in	Computed difference
Circumference	79.21 in	79.80 in	+0.7%	Within tolerance
Speedo	0.0%	+0.7%	+0.7%	Within tolerance

Current tireLooks valid

New tireLooks valid

Market

Units

✓ Within toleranceDiameter +0.7% (+0.19 in) · US (~3%)

Diameter+0.7%+0.19 in

Speedo @ 60+0.7%60 mph → 60.4 mph

Sidewall-0.91 inWidth +1.57 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.

195/60 R16 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″ `185/70R15`	-0.1%	-0.1%
OE `195/60R16`	+0.0%	+0.0%
+1″ `175/60R17`	+0.2%	+0.2%
+2″ `305/30R18`	-0.0%	-0.0%

What changed

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