All You Need to Know About 37X13.50R17 Tires

A 37X13.50R17 tire is a wide radial flotation tire combining a nominal 37-inch overall diameter, a 13.5-inch section width, radial construction (the "R"), and a 17-inch wheel diameter. This is the radial counterpart to the bias-ply 37x13.50-17 size - same nominal dimensions, fundamentally different construction, and considerably broader market availability.

37X13.50R17 Size Quick Specs

The following specifications apply to 37X13.50R17 as a size class. Actual measured diameter and approved rim width ranges can vary slightly between individual tire models; always confirm with the manufacturer's published inflated dimensions.

Note on actual diameter: All flotation tires, including 37X13.50R17, measure smaller than their stated nominal size when mounted and inflated. Verify the manufacturer's published inflated diameter before purchase.

What 37X13.50R17 Means - Notation Explained

• 37 = nominal tire height in inches
• 13.50 = nominal tire width in inches
• R = radial construction
• 17 = wheel diameter in inches

The "R" is what separates 37X13.50R17 from the bias-ply 37x13.50-17. Radial construction means the internal cords run at 90 degrees to the centerline of the tire, with a separate belt package stabilizing the tread. This geometry generates less heat per revolution at highway speeds, extends tread life compared to bias-ply construction, and produces more predictable handling on paved roads - all relevant for trucks that divide time between highway commuting and trail use.

37X13.50R17 vs 37x13.50-17: Why Construction Matters

The same nominal 37-inch, 13.5-inch-wide tire is available in both radial and bias-ply form. The table below identifies the performance differences that determine which construction is appropriate.

37X13.50R17 vs 37X12.50R17: Width Difference

Both 37X12.50R17 and 37X13.50R17 are 37-inch radial flotation tires on 17-inch wheels, distinguished only by section width. Both are 37-inch radial flotation tires. The 37X13.50R17 is one inch wider, which increases the contact patch on soft terrain. That extra width also increases the risk of rubbing at fenders, suspension arms, and inner liners, and increases steering effort on pavement. For vehicles where fitment clearance is tight, the 37X12.50R17 is the easier-fitting option because its narrower section clears factory and mildly modified fender openings with less trimming.

Fitment Notes for 37X13.50R17

The 13.5-inch section width of 37X13.50R17 requires specific attention to several fitment variables beyond just diameter clearance:

• Wheel offset and backspacing: The 13.5-inch section extends further inboard and outboard than a 12.5-inch tire on the same wheel. A wheel with insufficient positive offset can allow the inner sidewall to contact the leaf spring or control arm under load.
• Fender clearance at 13.5-inch section width: The tire should be measured at rest and through full steering lock and compression, not just at ride height.
• Steering lock clearance: Wider tires physically reduce the available lock angle before contact with the fender or inner liner. This must be tested with the specific wheel offset and backspacing chosen.
• Suspension travel: A tire that clears at rest can rub at full compression. Bump-stop height may need adjustment.
• Mud flap interference: 13.5-inch-wide tires commonly contact factory mud flaps that clear a 12.5-inch tire on the same vehicle.

Even on vehicles that accommodate 37X12.50R17 with minimal modification, the extra inch of width in 37X13.50R17 frequently requires fender trimming or flare extensions.