265/70 R17 vs 285/65 R18

285/65 R18 is outside the configured tolerance for 265/70 R17: +3.1% diameter and +3.1% speedometer effect.

Geometric comparison

285/65 R18 is outside the configured tolerance for 265/70 R17: +3.1% diameter and +3.1% speedometer effect.

Geometric comparison
Metric	This size: 265/70 R17	Alternative: 285/65 R18	Difference	Verdict
Overall diameter	31.61 in	32.59 in	+3.1%	Too tall
Section width	10.43 in	11.22 in	+0.79 in	Computed difference
Sidewall height	7.30 in	7.29 in	-0.01 in	Computed difference
Circumference	99.29 in	102.37 in	+3.1%	Too tall
Speedo	0.0%	+3.1%	+3.1%	Outside tolerance

Compare sizes

Current tireLooks valid

New tireLooks valid

Market

Units

High fitment riskOut of tolerance · Diameter +3.1% (+0.98 in) · US (~3%)

High fitment risk · This rating covers tire geometry only, not vehicle compatibility.
Diameter +3.1% · Ride-height change +0.49 in.
Speedometer reads low · 60 mph → 61.9 mph.
Sidewall -0.01 in · Width +0.79 in.

Diameter+3.1%+0.98 in

Speedo @ 60+3.1%60 mph → 61.9 mph

Sidewall-0.01 inWidth +0.79 in

Ride-height change+0.49 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.

Methodology

Before 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: 31.61 in 32.59 in+0.98 in
Sidewall: 7.30 in 7.29 in-0.01 in
Width: 10.43 in 11.22 in+0.79 in
Circumference: 99.29 in 102.37 in+3.1%
Revs / mile: 638 619
Speedo @ 60: 60 mph 61.9 mph+3.1%
Ride-height change: 0.00 in +0.49 in
True distance per 100 indicated: 100 mi 103.1 mi+3.1%

Current — 265/70 R17
New — 285/65 R18
Grounded to the road: the axle rises +0.49 in.

Result report

265/70 R17 285/65 R18 · High fitment risk · Out of tolerance

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Markdown link

[265/70 R17 vs 285/65 R18 Tire size comparison](https://tirefitlab.com/tire-size-calculator/?from=265%2F70+R17&to=285%2F65+R18&market=us)

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

In-tolerance alternative sizes

In-tolerance alternative sizes
Size	Diameter	Speedo @ 100	Use this
OE `265/70R17`	+0.0%	+0.0%

265/70 R17 · 285/65 R18 · Methodology

Technical check: 2026-06-28

What changed

Checked generated routes, metadata, sitemap inclusion and localized page rendering.

Methodology