Ford Bronco Raptor Wheel Fitment Guide — 6×135, OEM 37" Spec, and the Offset Sweet Spot

The Bronco Raptor runs a completely different axle and hub setup than the standard Bronco — borrowed directly from the F-150 Raptor. That means a different bolt pattern, a different centre bore, and a market that has almost nothing in common with the regular Bronco wheel aftermarket. This guide covers everything that matters before you order.

The Bolt Pattern Problem — Why Regular Bronco Wheels Won't Fit

This is the most important fact on this page. The standard Ford Bronco — including top-spec Sasquatch, Badlands, and Wildtrak trims — runs a 6×139.7 bolt pattern with a 93.1mm centre bore. Every aftermarket wheel built for the regular Bronco uses these specs.

The Bronco Raptor uses the heavy-duty axles and massive brake assembly from the F-150 Raptor. This changes everything:

• Bolt pattern: 6×135
• Centre bore: 87.1mm
• Wheel nut thread: M14×1.5

A wheel drilled for 6×139.7 will not bolt onto the Bronco Raptor. The bolt circle is physically different. When searching for aftermarket wheels, ignore the standard Bronco market entirely — look specifically for Bronco Raptor fitment or F-150 Raptor specs (6×135, 87.1mm).

Why the Hub Is Different

The Bronco Raptor's wider track width — achieved through the F-150 Raptor solid rear axle and reinforced front axle — places the hub significantly further outboard than the standard Bronco. Ford adapted the F-150 Raptor's bolt pattern (6×135) and hub bore (87.1mm) along with the whole axle assembly. The result is a truck that shares almost no wheel compatibility with the model it's based on, despite sharing the same body.

Factory Spec

• OEM wheel: 17×8.5 at ET+34 / ET+35
• OEM tyre: 37×12.50R17 LT BFGoodrich All-Terrain T/A KO2

The factory offset of ET+34 to ET+35 is intentionally high — the hub sits far outboard, and running that much positive offset pulls the wheel face inward to keep the tyre within the fender line. This is why the stock Bronco Raptor looks proportional from the factory despite running 37" rubber: the geometry is working hard to contain the tyre within the arch.

Offset Guide — What Changes When You Go Lower

ET+12 to ET+25 — The Sweet Spot

Reducing offset from the stock ET+34/+35 pushes the wheel outboard — creating visible poke beyond the fender edge without inducing contact at the inner arch. ET+18 to ET+25 is the most commonly recommended range: the tyre face sits noticeably wider than stock, the stance reads as aggressive and purposeful, and at maximum suspension articulation or full steering lock the tyre still clears inner fender components. This is the offset range that transforms the visual character of the Bronco Raptor while remaining functionally safe on trail.

ET0 and Below — Lift Required

At ET0 or negative offset on stock suspension, the tyre arc during full flex or full steering lock sweeps into the inner arch and contact with the inner fender liner and suspension components occurs. This is not a clearance issue that disappears with trimming — the geometry of the axle at maximum articulation physically places the tyre into the body at these offsets without a lift to change the suspension travel arc. ET0 and negative offsets are lift-only territory on the Bronco Raptor.

Wheel Diameter

17" — Off-Road

17×8.5 or 17×9 is the clear choice for any build that spends time on genuine terrain. Maximum sidewall height means better absorption of rock impacts, more tyre flex on uneven surfaces, and more cushion on washboard desert roads. The factory chose 17" with a 37×12.50R17 for exactly this reason — sidewall is performance on this platform.

18" and 20" — Street / Show

20×9 is popular for builds that prioritise visual impact over off-road performance. The reduced sidewall runs harder over rough terrain and provides less flex at low pressure, but the wider face fills the arch more aggressively and allows for more diverse tread pattern options. Functionally a compromise — visually a strong statement on the Bronco Raptor's wide body.

The Beadlock Reality

The Bronco Raptor leaves the factory with beadlock-capable wheels — not functional beadlocks. The outer ring visible on the OEM wheel is a decorative beauty ring. The wheel functions as a standard street wheel and provides no additional bead retention at low pressure.

To convert to a functional beadlock — where the outer ring mechanically clamps the tyre bead to allow dropping to 0.5 bar (7 PSI) on technical rock terrain without the tyre spinning off the rim — the Ford Performance Functional Beadlock Ring Kit must be purchased separately and the wheel re-assembled. This is a significant additional cost and adds weight to the wheel, but it enables the kind of low-pressure rock crawling the platform was designed for.

If genuine beadlock function matters for your build, a purpose-built forged beadlock wheel is a more weight-efficient alternative to converting the OEM unit.

Tyre Size Roadmap

37" — Stock (No Mods)

37×12.50R17 — the factory size on the Bronco Raptor. Fits at stock height with ET+34/+35 OEM offset without any arch modification. At reduced offsets (ET+18 to ET+25), the same tyre fits cleanly with no contact on stock suspension.

38–40" — Requires Lift

Moving beyond 37" requires a minimum 2" suspension lift, replacement of the front upper control arms (to restore correct geometry under the additional lift), and trimming of inner plastic arch components. 40" builds are achievable but represent a full suspension re-engineering project — not a simple tyre upgrade. Budget accordingly.

Tyre Recommendations

All-Terrain / Daily

• BFGoodrich All-Terrain T/A KO2 — the factory tyre on the Bronco Raptor. Proven across desert, rock, and sand. An excellent baseline that most owners run for thousands of miles before looking elsewhere.
• Toyo Open Country A/T III — quieter on highway than the KO2, still capable on trail. Popular for builds that cover long distances between trailheads.

Rugged Terrain / Hybrid

• Nitto Ridge Grappler — the most common upgrade over the stock KO2 for owners who want a more aggressive sidewall and visual profile while maintaining reasonable highway manners. Widely available in 37×12.50R17.
• BFGoodrich Mud-Terrain T/A KM3 — for builds that spend the majority of time on rock or mud and accept the highway noise that comes with a full MT pattern.