235/70 R17 vs 35x12.50 R20

35x12.50 R20 is outside the configured tolerance for 235/70 R17: +16.9% diameter and +16.9% speedometer effect.

Geometric comparison

35x12.50 R20 is outside the configured tolerance for 235/70 R17: +16.9% diameter and +16.9% speedometer effect.

Geometric comparison
Metric	This size: 235/70 R17	Alternative: 35x12.50 R20	Difference	Verdict
Overall diameter	29.95 in	35.00 in	+16.9%	Too tall
Section width	9.25 in	12.50 in	+3.25 in	Computed difference
Sidewall height	6.48 in	7.50 in	+1.02 in	Computed difference
Circumference	94.10 in	109.96 in	+16.9%	Too tall
Speedo	0.0%	+16.9%	+16.9%	Outside tolerance

Compare sizes

Current tireLooks valid

New tireLooks valid

Market

Units

Not recommendedOut of tolerance · Diameter +16.9% (+5.05 in) · US (~3%)

Not recommended · This rating covers tire geometry only, not vehicle compatibility.
Diameter +16.9% · Ride-height change +2.52 in.
Speedometer reads low · 60 mph → 70.1 mph.
Sidewall +1.02 in · Width +3.25 in.

Diameter+16.9%+5.05 in

Speedo @ 60+16.9%60 mph → 70.1 mph

Sidewall+1.02 inWidth +3.25 in

Ride-height change+2.52 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: 29.95 in 35.00 in+5.05 in
Sidewall: 6.48 in 7.50 in+1.02 in
Width: 9.25 in 12.50 in+3.25 in
Circumference: 94.10 in 109.96 in+16.9%
Revs / mile: 673 576
Speedo @ 60: 60 mph 70.1 mph+16.9%
Ride-height change: 0.00 in +2.52 in
True distance per 100 indicated: 100 mi 116.9 mi+16.9%

Current — 235/70 R17
New — 35x12.50 R20
Grounded to the road: the axle rises +2.52 in.

Result report

235/70 R17 35x12.50 R20 · Not recommended · Out of tolerance

Copy/print uses this page state only; TireFitLab does not create an account or store a server-side report.

Embed or cite this result

HTML iframe

<iframe src="https://tirefitlab.com/embed/tire-comparison/?from=235%2F70+R17&to=35x12.50+R20&market=us" title="235/70 R17 vs 35x12.50 R20 Tire size comparison" loading="lazy" width="720" height="330" style="width:100%;max-width:720px;border:0" referrerpolicy="strict-origin-when-cross-origin"></iframe>

Markdown link

[235/70 R17 vs 35x12.50 R20 Tire size comparison](https://tirefitlab.com/tire-size-calculator/?from=235%2F70+R17&to=35x12.50+R20&market=us)

Open embed preview

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 `235/70R17`	+0.0%	+0.0%

235/70 R17 · 35x12.50 R20 · Methodology

Technical check: 2026-06-28

What changed

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

Methodology