AN OVERVIEW
Let’s face it, slapping on a set of 40s is practically a rite of passage in the Jeep world; but while “bigger is better” might win style points, the real truth is that every jump in tire size affects your Jeep’s driving characteristics and fuel economy. Not to mention that big tires significantly speed up wear on many components. Period.
We’re kicking off the Zero to Jeep Hero series by breaking down what’s realistically required to run the four most popular tire sizes in the off-road world: 33", 35", 37", and 40+". Whether you’re building for the trails or the gram, this is where smart upgrades start.
33” Tires – The Perfect First Step
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Lift required: None if a Rubicon, but a leveling kit can really finish the look. Otherwise a 1" should be more than enough for all other trims.
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Trimming: The bumper closeout panels on the JL plastic bumpers will need to be trimmed or removed to fit 33s without a lift.
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Other mods? In order to avoid the tires rubbing on the control arms, a set of wheel spacers or higher offset wheels will be required. We highly recommend the Spidertrax wheel spacers, as cheap wheel spacers can destroy your wheel bearings in no time at all.
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Daily driving impact: Negligible, especially for 33” all terrains.
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Ideal for: Light trails, improved stance, better grip and clearance off road.
Notes:
Upgrading to 33s is one of the top mods to do first. It’s the easiest upgrade for new Jeep owners who want better off-road performance without breaking the bank or daily drivability. Most stock Rubicon trims can fit them with no lift at all, and can even be optioned from the factory.
35” Tires – The Sweet Spot for Most Builds
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Lift required: 2”- 2.5" suspension lift recommended (Rubicons can fit 35s with no lift but rubbing can occur depending on wheels and tires)
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Trimming: As long as an appropriate lift is installed trimming should not be required.
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Other mods:
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New wheels or wheel spacers to avoid rubbing the tires on the control arms.
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Depending on how much flex your kit provides and your wheel/tire combo, a new stubby front bumper may be required because of rubbing. Shop our premium US made bumpers HERE.
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A re-gear to 4:56s or 4:88s is highly recommended (especially for automatic Jeeps)
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Upgraded steering (Drag Link and Tie Rod) is highly recommended
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With a 2.5” lift you are at the absolute limit for the stock driveshafts, and we highly recommend getting HD driveshafts from either TOM WOODS or ADAMS driveshafts
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Steering stabilizer upgrades
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Daily driving impact: Slight MPG drop, minor handling changes
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Ideal for: Moderate off-roaders, weekend warriors, overlanders
Notes:
Upgrading to 35s requires more money and time if you want your Jeep to drive well and last, ESPECIALLY if you plan on off-roading. A bad lift will ride horribly, wear out fast, and break other things along the way.
When we say a “lift kit”, we DO NOT mean a set of springs and shocks. We mean a lift KIT.
At BARE MINIMUM a lift kit should include:
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Multi-rate springs
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Spring pads
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Dampers (Shocks)
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Bump stops or bump stop extensions
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Control arms: 2 front lowers is the MINIMUM, all 8 is best
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Track bars and/or track bar re-location brackets
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New, longer sway bar links
A truly complete kit will come with even more than this
A TIP FROM TEAM ORC
We are about to enter the "big tire" category.
You can absolutely run 37s and 40s slammed to the ground on a MINIMAL lift to keep things low and stable off road (LCOG build) This is absolutely the way for ultimate performance for JLs (JTs need to be a bit higher due to wheelbase). You will need to work with a PREMIERE shop or be very educated on suspension to make this work. Big bump stop extensions, oversized dampers, a lot of trimming, highline fenders or a fender delete and more will be required.
INTERESTED IN BUILDING A BIG TIRE LCOG JL?
Give our friends a ring!
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COLORADO- TRAIL JEEPS
37” Tires – The jump to a “big tire”
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Lift: 2.5” - 3.5” Full suspension system.
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Trimming: Moderate to significant depending on the suspension system used.
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Other mods:
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Everything we have already listed for running 35s
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A stubby front bumper like our SPORT SERIES as 37s can rub the OE bumpers and most mid or full width bumpers at full flex.
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Beef up your axles (yes, even the JLR D44s) with shafts, a truss, ball joints and definitely C gussets.
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Re-gearing is an absolute must, and we recommend either 4:88 or 5:13 gears
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A hydro assist kit from PSC is HIGHLY RECOMMENDED, but if that is out of your budget then an upgraded steering damper is a must.
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Daily driving impact: Noticeable — expect MPG loss and softer handling, the jeep may feel a little more “floaty.”
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Ideal for: Weekend warriors, committed daily drivers, and dedicated trail rigs.
Notes:
You’re officially out of beginner territory. 37s give you massive traction and clearance, but they demand serious supporting mods. Without proper upgrades, you’ll wear out stock components fast — or worse, leave yourself stranded on the trail.
40”+ Tires – Full Send Territory
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Lift: When comparing lifts between 37s and 40s the components remain mostly the same other than springs for lift height. The difference is what's required elsewhere around the vehicle; so let's dive into that.
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Trimming: If you have a Rubicon you can trim the Mopar highline fenders (Fender chop) but otherwise you're going to need aftermarket high clearance fenders. Some grinding to the tub may also be necessary depending on your build and how aggressive your tires are.
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Other mods: If you are building a show rig or want to just hit some harder trails we've pretty much already covered the most important upgrades. However if you have the “wow that's a crazy obstacle... I'm gonna try it ” type of personality; one ton axles, full hydro, coilovers, long arms, and more is probably in your future.
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Daily driving impact: Varies greatly on the components used
Notes:
If your thinking about 40s you probably want to tackle the most extreme parks in the world like AOP and Chocco; and (should) have the wallet to support it. If you are ready for this step then give us a call and we can give some recommendations and connect you with a high end shop in your area.
OFF ROAD CONCEPTS
(828)860-6024
SUPPORT@ORCDESIGNLLC.COM
IN SUMMARY
Tires are one of the most exciting parts of a Jeep build, but going bigger without understanding the "why and what else" can lead to a disappointing ride, or worse, expensive repairs.
At Off Road Concepts, we believe every upgrade should serve a purpose, not just look cool. Whether you're shopping for 33s or planning for 40s, start with a solid understanding of what your Jeep needs to perform and stay reliable.
Our industry recommendations:
Suspension Systems:
Dampers: