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Will 40-inch tires fit a JL Wrangler Rubicon?
Fitment answer · Updated October 27, 2026
Short answer
Only with a serious build. 40s on a JL Rubicon usually mean roughly 3.5 to 4.5 inches of lift or more, high-clearance fenders, long bump stops, upgraded steering, a deep regear and often stronger axles. It is a dedicated trail setup, not a simple tire swap.
Shop the gear for this build ↓ Tires, deflators and a compressor picked for this setup.
What it usually takes
- A tall lift with long-travel parts or a long-arm kit.
- High-clearance fenders and trimmed or removed liners.
- Heavy-duty steering (tie rod, drag link, often hydraulic assist).
- Wheels with the right backspacing and beadlocks for many owners.
Regearing
40s need deep gears, commonly around 5.13 to 5.38, and stronger axle shafts or axles are common. Compare ratios in the Tire & Gear Calculator before you buy gears.
Daily driving caveats
- Big drops in fuel economy, braking and highway comfort.
- Higher wear on ball joints, steering and wheel bearings.
- Check local laws on tire coverage and bumper height.
Gear for this build
- Mud-terrain tires (search) — Louder on the highway; buy for real mud use.
- YUNPEAK 1.26" × 30' kinetic recovery rope — Bigger tires, bigger trails: carry recovery gear.
- Staun tire deflators — Repeatable trail pressures.
- VIAIR 88P portable compressor — Air back up before the highway.
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FAQ
Can a stock-suspension Rubicon run 40s?
No. 40s need a tall lift and major supporting changes.
Is 37 a better choice?
For most owners who still drive on the street, yes. See 37s on a JL Rubicon.
Do I need new axles for 40s?
Many builders upgrade axle shafts or swap to heavier axles.
Check your numbers
Use the free Tire & Gear Calculator to see speedometer error, highway RPM and a regear target, or ask TekJeep AI on the homepage with your year, trim, lift and wheel specs.
Related guides: All-terrain & mud-terrain tires · JK 2.5" lift overview
More fitment answers: 35s on a JL Sport · 33s on a stock JL · 37s on a JL Rubicon · 35s on a stock JL Rubicon · 35s on a JL with a 2.5" lift · 33s on a leveled or 2.5" lifted JL · 35s on a JL with a 3.5" lift · 37s on a JL with a 3.5" lift
Fitment disclaimer: Clearance depends on exact tire size, wheel specs, suspension and how hard you flex. Confirm with your tire shop or installer before buying.
Tire size how-tos: How to read a tire size · Bolt pattern & backspacing · Regearing for bigger tires · Tire pressure after upsizing · Speedometer error · Rubbing fixes