42x13.50-17 Tire Size

All You Need to Know About 42x13.50-17 Tires

A 42x13.50-17 tire is an extreme flotation size with a nominal 42-inch overall diameter, a 13.5-inch section width, and a 17-inch wheel diameter. The hyphenated format - 42x13.50-17, not 42X13.50R17LT - indicates bias-ply (non-radial) construction. At 42 inches nominal diameter, this tire size is beyond the clearance envelope of virtually all stock or mildly modified street-legal trucks and is primarily used on purpose-built competition vehicles and extreme off-road rigs where casing conformability at low speeds outweighs all other considerations.

42x13.50-17 Size Quick Specs

The following specifications reflect the 42x13.50-17 size class. Production of bias-ply tires at this diameter is extremely limited; confirm current availability and published dimensions with the specific manufacturer before planning a build around this size.

What 42x13.50-17 Means - Notation Explained

• 42 = nominal tire height in inches
• 13.50 = nominal tire width in inches
• -17 = 17-inch wheel diameter; the hyphen confirms bias-ply construction

42x13.50-17 is not the same as 42X13.50R17LT. The radial LT version is the far more practical choice for any vehicle that operates on pavement - radial construction manages heat better at speed, wears more predictably, carries a higher load rating, and handles more precisely.

Bias-ply 42-inch tires are a deliberate competition choice: the casing's diagonal cord structure allows greater low-speed flex and terrain conformance, which matters in static rock crawling scenarios where the tire's ability to mold around an obstacle surface is the primary performance variable. That same flex becomes a liability at highway speeds, generating excessive heat and reducing casing life.

42x13.50-17 vs 42X13.50R17LT: Construction

Both 42x13.50-17 and 42X13.50R17LT tires share the nominal 42-inch diameter, 13.5-inch section width, and 17-inch wheel fitment. The construction difference determines the appropriate application entirely.

42x13.50-17 vs 40x13.50-17: Height Comparison

Both 42x13.50-17 and 40x13.50-17 tires are bias-ply 13.5-inch-wide flotation tires on 17-inch wheels, differing only in nominal diameter.

The 42x13.50-17 is two inches taller in nominal diameter than the 40x13.50-17, adding roughly 1 inch of axle clearance. The 42-inch tire's circumference (~132 inches) versus the 40-inch (~125 inches) means a proportionally greater gear ratio correction requirement, more steering load, longer braking distances, and greater rotating mass stress on axle and drivetrain components.

42x13.50-17 Fitment

A nominal 42-inch tire requires major vehicle modification on virtually any platform:

• Large suspension lift - 6"+ is a typical minimum, with many platforms requiring more for adequate full-travel clearance
• Significant body clearance work, including cutting of fenders, inner liners, and sometimes body panels
• Axle regearing, typically to 4.88 or lower on Jeep JK/JL and common truck platforms, to compensate for the 42-inch rolling circumference
• Strengthened steering components - tie rods, drag links, and the steering box must be rated for the increased moment arm the larger tire creates
• Upgraded brake components to handle the increased rotating mass and the longer stopping distances a 42-inch tire produces
• Axle shaft and differential strength evaluation - the torque multiplication of low gearing applied through a 42-inch tire substantially increases stress on ring and pinion gears and axle shafts
• Full drivetrain stress review across u-joints, transfer case, and transmission output shaft

For the radial LT version of this size, see 42X13.50R17LT.