35x11.50R17 vs 35x12.50R17 — one inch of width, nothing else

The narrow 35 against the standard one, where the arithmetic finds nothing and availability finds everything.

Drawn to scale from the size codes. Solid outline is 35x11.50R17; dashed outline is 35x12.50R17. The bars below each tire are section width at the same scale.

35x12.50R17 is 0.00 in taller than 35x11.50R17 (0.00%) and 1.00 in wider. A speedometer calibrated for 35x11.50R17 would under-read by 0.00%.

Measured against each other

Overall diameter
35.00 in35.00 in0.00 in (0.00%)
Section width
11.50 in / 292 mm12.50 in / 318 mm+1.00 in (+8.70%)
Sidewall height
9.00 in9.00 in0.00 in
Circumference
110.0 in110.0 in0.0 in
Revolutions per mile
576.2576.20.0
Ride height at the axle
——0.00 in
Speedometer reading
——0.00% under-read

Dimension	35x11.50R17	35x12.50R17	Change
Overall diameter	35.00 in	35.00 in	0.00 in (0.00%)
Section width	11.50 in / 292 mm	12.50 in / 318 mm	+1.00 in (+8.70%)
Sidewall height	9.00 in	9.00 in	0.00 in
Circumference	110.0 in	110.0 in	0.0 in
Revolutions per mile	576.2	576.2	0.0
Ride height at the axle	—	—	0.00 in
Speedometer reading	—	—	0.00% under-read

Calibrated for 35x11.50R17, running 35x12.50R17

Dial reads 30: 30.0 mph
Dial reads 50: 50.0 mph
Dial reads 70: 70.0 mph
Odometer counts 100: 100.0 mi covered

Change either size in the comparison tool, or see the full speed table in the speedometer error calculator.

Identical height, identical sidewall, identical circumference, identical revolutions per mile. One inch of casing separates these two tires and that is the entire list.

Nothing to calculate

Speedometer error: zero. Odometer drift: zero. Ride-height change: zero. Effective gearing change: zero. There is no arithmetic to perform on this pairing beyond the width figure, which is 1.00 in, or 8.70%.

That makes it one of the two pages on this site where the comparison tool's job is done before it starts — the other being 33x10.50R17 against 33x12.50R17, which isolates two inches instead of one.

The proportions still differ

There is no profile figure anywhere in either code. Work them out and the narrow tire is a 78-series while the wide one is a 72 — six series apart on tires of identical height, because the same 9.00 in of sidewall is a larger fraction of a smaller casing.

So they are not the same tire in two widths. They are two different shapes that happen to reach the same diameter.

Where the inch goes

Beside the tire, at full lock, and onto the wheel. A 12.50 in section wants a wider rim than an 11.50 in one, so the two are not always interchangeable on the same wheels without the narrow tire sitting stretched or the wide one crowning.

Unsprung mass follows width too, and an inch of casing across four tires is not nothing on a vehicle where the tires are already the heaviest rotating parts.

The availability problem

35x12.50R17 is stocked by essentially every manufacturer that makes an off-road tire. 35x11.50R17 is made by very few, in very few patterns, and is frequently unavailable in the compound someone wants.

For most buyers that settles it before the geometry is consulted, and it is the reason the narrow 35 remains a specialist choice for vehicles that genuinely cannot take the extra inch.

The narrow option one size down

At 33 inches the narrow choice is better supported and the width saving is larger — two inches rather than one — which is why the narrow-tire argument is more often made there than here.