When it comes to enhancing your Jeep’s off-road capabilities, installing a set of 37-inch tires ranks among the most impactful upgrades you can make. These massive tires provide game-changing ground clearance, traction, and approach angles, transforming a capable Jeep into a serious off-road machine. However, choosing the right 37-inch tires requires careful consideration of numerous factors beyond just size and brand. From compatibility and gearing to on-road behavior and budget, this comprehensive guide covers everything you need to know before making your purchase. Whether you’re a weekend trail runner or a hardcore rock crawler, understanding these key points will help you select the perfect set of rubber for your Jeep.

Benefits of Upgrading to 37-Inch Tires

Moving from stock-sized tires to 37-inch tires brings several distinct advantages that dramatically improve off-road performance.

  • Increased Ground Clearance: A larger tire diameter lifts the axle and chassis higher, reducing the risk of getting hung up on rocks, logs, or ruts. The extra clearance is often the difference between crawling over an obstacle or needing a winch.
  • Improved Traction: A larger contact patch and deeper tread lugs provide superior grip on loose surfaces like sand, mud, and gravel. Combined with proper tread design, 37-inch tires can claw through terrain that would stop smaller tires.
  • Better Approach, Breakover, and Departure Angles: Larger tires effectively increase the distance from the ground to the lowest point of the vehicle, which improves obstacle climbing capability. This is especially valuable for rock crawling.
  • Enhanced Stability at Low Speeds: The wider footprint and taller sidewall can help the vehicle feel more planted when traversing uneven terrain at crawling speeds.
  • Visual Impact: Let’s not ignore the aggressive, purpose-built look. 37-inch tires give a Jeep a commanding, ready-for-anything appearance that smaller tires simply cannot match.

Understanding Tire Specifications

Before diving into specific tire models, it’s essential to grasp the key tire specifications and how they affect performance on and off the road.

Tire Width and Aspect Ratio

37-inch tires come in several widths, typically ranging from 12.5 inches to 14.5 inches. Wider tires offer a larger footprint for flotation in sand and increased traction in loose conditions, but they also add weight, increase rolling resistance, and can negatively impact fuel economy. The aspect ratio, which describes sidewall height as a percentage of width, also matters. A lower aspect ratio (e.g., a “37×12.50R17” has a shorter sidewall relative to a “37×13.50R17”) provides better on-road handling and less sidewall flex, while a taller sidewall offers more compliance and cushioning on rough trails. Striking the right balance depends on your primary driving environment.

Tread Pattern and Compound

Tread pattern is the most visible differentiator between tire types. Aggressive, open-lug designs excel in mud and rocks because they self-clean and bite into soft surfaces. However, they tend to be noisier on pavement and wear faster. Less aggressive all-terrain patterns compromise some off-road bite for quieter, smoother highway cruising and longer tread life. The rubber compound also plays a role: softer compounds provide better grip on slickrock and wet surfaces but wear quickly on hot asphalt; harder compounds last longer but may lack traction in certain situations. Many off-road tires use a dual-compound design with a harder center for durability and softer shoulder lugs for side-bite.

Load Rating and Speed Rating

37-inch tires often carry a Load Range C, D, or E, which corresponds to the maximum weight they can safely support. For a Jeep Wrangler or similar SUV, Load Range C (6-ply rated) is usually sufficient and provides a more comfortable ride. Load Range E (10-ply) is heavier, stiffer, and better suited for heavy loads or towing, but it can be overly harsh for daily driving. Speed ratings (e.g., Q, R, S) indicate the maximum safe speed; most off-road tires have a Q rating (100 mph) which is more than adequate for highway use. Always choose a load rating that matches your vehicle’s gross vehicle weight rating.

Types of 37-Inch Tires

Not all 37-inch tires are created equal. Selecting the right type for your typical terrain is critical.

All-Terrain Tires

All-terrain tires are the jack-of-all-trades option. They provide acceptable traction in mud, sand, and rocks while maintaining good on-road manners with low noise and decent tread life. Brands like the BFGoodrich All-Terrain T/A KO2 and Falken WildPeak A/T3W are popular choices. These tires are ideal for Jeep owners who drive to the trail, do moderate off-roading, and still use their vehicle as a daily driver. However, in extreme conditions like deep mud or technical rock crawling, they may lack the bite of dedicated mud-terrain tires.

Mud-Terrain Tires

Mud-terrain tires feature aggressive tread blocks with large voids and deep lugs designed to self-clean and provide maximum traction in loose, slippery conditions. They excel in mud, slush, and soft soil. However, they come with trade-offs: increased road noise, harsher ride quality, and faster tread wear. Examples include the BFGoodrich Mud-Terrain T/A KM3 and Toyo Open Country M/T. If you frequently tackle deep mud bogs or gnarly trails, these tires are worth the compromise for the grip they offer.

Rock-Crawling Tires

Rock-crawling tires are a subset of mud-terrain designs optimized for hard rock surfaces. They feature sidewall armor, reinforced bead constructions, and tread designs that wrap around the sidewall to provide grip on ledges and cracks. Tires like the Nitto Trail Grappler M/T and Cooper Discoverer STT Pro offer excellent rock-crawling performance. They tend to be stiffer and heavier but provide unmatched durability and grip in technical terrain.

Choosing a reputable brand helps ensure consistent quality, reliable performance, and good customer support. Here’s a closer look at some top contenders.

BFGoodrich

BFGoodrich has been a staple in off-road tires for decades. Their KO2 all-terrain and KM3 mud-terrain are benchmark choices. BFGoodrich tires are known for durable sidewalls (especially the Krawl-Tek compound in the KM3) and excellent all-around performance. They are widely available and come with a solid reputation for off-road durability.

Goodyear

Goodyear offers the Wrangler family of off-road tires, including the Wrangler Duratrac (all-terrain/light mud hybrid) and the Wrangler MT/R with Kevlar. Goodyear tires typically provide good on-road manners and strong off-road traction. Their fuel-saving technology (in some models) can help mitigate the efficiency drop from larger tires.

Falken

Falken has gained a strong following with the WildPeak M/T and A/T lines. Their 3D sipe technology improves wet traction, and their rugged sidewalls resist punctures. Falken tires offer a good balance of price and performance, often competing with premium brands at a slightly lower cost.

Nitto

Nitto is a favorite among serious off-roaders, especially for rock crawling and overlanding. The Trail Grappler M/T and Ridge Grappler (hybrid all-terrain) are highly regarded for their sidewall strength and traction. Nitto tires tend to be heavier but very durable.

Cooper

Cooper tires, including the Discoverer STT Pro and AT3 XLT, offer excellent value. They use Armor-Tek3 construction for cut and chip resistance. Cooper is known for producing quiet, well-mannered tires that still handle tough trails.

Compatibility Considerations

Simply bolting on 37-inch tires is rarely straightforward. Multiple compatibility factors must be addressed to ensure proper fitment and safe operation.

Wheel Size and Offset

Most 37-inch tires are designed for 17-inch to 18-inch wheels, though some fit 20-inch wheels. The wheel width must match the tire’s approved rim width range. Offset (the distance from the wheel’s mounting surface to its centerline) and backspacing determine how far the tire sits inside or outside the wheel well. Incorrect offset can cause rubbing on suspension components or fenders. For stock axles, a common recommendation is a wheel with 4.5 to 4.75 inches of backspacing and zero to negative offset to push the tire outward for clearance.

Lift Kit Requirements

Almost every Jeep Wrangler or Gladiator will require a suspension lift to fit 37-inch tires without rubbing. A minimum of 2.5 to 3 inches of lift is typically needed for a JK or JL Wrangler, while a JK or JL on 37s often runs 3–4 inches of lift for full articulation. The lift must provide clearance for the tires at full flex (suspension compression). In addition, bump stops may need to be extended to prevent the tires from contacting the fenders during off-road cycles.

Fender and Body Modifications

Even with a lift, many rigs require fender trimming or the installation of aftermarket high-clearance fenders to avoid rubbing. Flat-fender or tube-fender kits can gain several inches of clearance. Some owners also cut the pinch weld seam inside the fender well. Without these modifications, you may experience rubbing during turns or over bumps, which can damage tires and bodywork.

Axle Strength and Gear Ratios

Stock axles, especially Dana 30s (front) and Dana 35s (rear) on older Wranglers, may not hold up well to 37-inch tires under heavy throttle or in tough terrain. Upgrading to Dana 44, Dana 60, or equivalent axles is recommended for durability. Additionally, 37-inch tires significantly alter the effective gear ratio, reducing engine RPM at highway speeds and robbing power. Regearing to lower axle ratios (e.g., 4.88:1 or 5.13:1) helps restore performance and ensures the transmission stays in the optimal power band. For automatic transmissions, 4.88 gears are common for 37s, while 5.13s are preferred for manual transmissions or heavier rigs.

Impact on Vehicle Dynamics

Switching to 37-inch tires changes how your Jeep behaves on and off the road. Understanding these effects helps you prepare and adapt.

Acceleration and Braking

Larger tires weigh more and have a higher rotational mass, which slows acceleration and increases stopping distances. The engine must work harder to spin them up, and the brakes need to dissipate more energy. Upgrading to bigger brakes (e.g., a big brake kit) or at least ensuring your stock braking system is in top condition is advisable. Driving style may need to become more cautious, especially in traffic.

Steering and Handling

Wider tires can increase steering effort, especially at low speeds. A properly calibrated steering stabilizer helps manage wheel shimmy and reduces feedback. The increased scrub radius from wider tires can also make the Jeep feel more wandery on the highway; adjusting caster angle via control arms can help stabilize the steering. Many owners add a heavy-duty steering damper to control vibrations.

Fuel Economy

Expect a significant drop in fuel economy—often 2 to 4 mpg or more—due to increased rolling resistance, aerodynamic drag (tires stick out), and the engine working harder. This is an unavoidable trade-off of large tires. Some owners regear to try to mitigate the loss, but the physical drag remains.

Installation Considerations

Installing 37-inch tires is not a simple swap. Professional installation is strongly recommended, but if you are doing it yourself, pay attention to these points.

Tire Mounting and Balancing

Large tires require specialized mounting machines to avoid damaging the bead. Balancing is critical to prevent vibration at highway speeds. Some tires are less round than others; dynamic balancing and a quality road-force balancer can identify issues. Consider using beadlock wheels (or simulated beadlocks) if you plan to air down frequently for off-road traction.

Alignment and Suspension Geometry

After installing 37-inch tires and a lift, a proper alignment is essential. Adjust toe-in, camber (if adjustable), and caster to ensure straight tracking and even tire wear. Many Jeeps benefit from aftermarket control arms to adjust caster and pinion angles. A bad alignment will rapidly wear expensive tires and make driving unsafe.

Brake and ABS Considerations

Larger tires can confuse the ABS system if the wheel speed sensors are not recalibrated. Some owners use a programmer (e.g., Superchips Flashcal or Tazer JL) to adjust the tire size in the vehicle’s computer. This corrects the speedometer, transmission shift points, and ABS/ESC behavior. Failure to recalibrate may result in a speedometer reading 5–10% too slow, which can affect fuel economy calculations and the odometer.

Maintenance Tips for 37-Inch Tires

Once installed, proper maintenance maximizes tire life and performance.

  • Check Air Pressure Frequently: 37-inch tires often run lower pressures than stock, typically 26–30 psi on-road and as low as 10–15 psi off-road. Use a quality gauge and inspect for leaks often, especially after off-road trips.
  • Rotate Tires Regularly: Every 5,000–7,000 miles. For 37-inch tires, a 5-tire rotation (including spare) is ideal to even out wear from the front axle, which often wears faster.
  • Inspect for Cuts, Punctures, and Sidewall Damage: After every off-road outing, look for cuts, bulges, or nails. Sidewall damage can be dangerous and may require replacement.
  • Monitor Tread Depth and Wear Patterns: Uneven wear may indicate alignment issues, over/under inflation, or suspension problems. Address them promptly to avoid premature tire replacement.
  • Keep Them Clean: Mud and debris can accelerate rubber degradation. Power washing after muddy runs helps preserve the tread and sidewalls.

Budget and Pricing Overview

The cost of a set of 37-inch tires varies widely based on brand, type, and load range. Here’s a general price breakdown per tire:

  • Budget Range ($200–$300): Often less-known brands or older designs. May have shorter tread life or poorer off-road performance. Suitable for occasional off-road use or tight budgets.
  • Mid-Range ($300–$450): Most popular options from brands like Falken, Cooper, and Goodyear. Offer good balance of on-road comfort and off-road traction. Longevity is decent.
  • Premium ($450–$650+): Flagship models from BFGoodrich, Nitto, Toyo. Advanced compounds, reinforced sidewalls, and proven performance in extreme conditions. Expect 40,000–50,000 miles of tread life with proper care.

Remember that the total investment includes mounting, balancing, valves, and potentially new wheels. A full set of five 37-inch tires can easily cost $2,000–$4,500, not including the lift kit, gears, or other required modifications. Plan your budget accordingly.

Common Myths About 37-Inch Tires

There are several misconceptions about running 37-inch tires. Let’s clear them up.

  • Myth: You can run 37s with just a leveling kit. In reality, almost every Jeep requires a proper lift to avoid rubbing, especially when off-road. Leveling kits only raise the front and are insufficient for full suspension travel.
  • Myth: Bigger tires always mean better off-road performance. Not true. Tires that are too large for the vehicle’s suspension, gearing, and axles can actually hinder performance due to excessive weight, loss of power, and reduced articulation. Properly sized tires (including 37s) for the build are key.
  • Myth: Lower tire pressure always improves traction. While airing down increases the contact patch, going too low can cause tire spin on the rim (burping) or sidewall damage. Use safe pressures and consider beadlocks for extreme deflation.
  • Myth: You don’t need to regear if you have enough power. Even a modified V8 can suffer from poor shift quality and excessive transmission heat without correct gearing. Regearing is about drivability and longevity, not just power.

Conclusion

Selecting the right 37-inch tires for your Jeep involves much more than picking a tire size. From understanding tire specifications and choosing the right tread type to ensuring your Jeep is properly lifted, geared, and braked, every decision affects the final driving experience. Take the time to research compatibility, set a realistic budget that includes necessary modifications, and invest in reputable brands known for off-road durability. When done correctly, a 37-inch tire upgrade transforms your Jeep into an exceptionally capable off-road vehicle that can tackle the toughest trails while still being driven to the trailhead. Use this guide as a starting point, and always consult with experienced Jeep builders or tire professionals if you have questions. Your next adventure awaits on those bigger, bolder tires.

For further reading, check out Tire Rack’s off-road tire guide, the Quadratec Jeep forum for real-world fitment experiences, and Jeep’s official maintenance resources for recommended tire care.