If you’re a Jeep Wrangler JL owner, you’ve probably daydreamed about upgrading to a larger set of tires for that commanding off-road look and improved performance. But, making the leap to bigger tires isn’t as simple as just swapping them out. To achieve the perfect fit, there are several factors to consider, including your Jeep’s trim level, suspension, wheel specs, and other key modifications. In this comprehensive guide, we’ll walk you through everything you need to know about choosing the right tire size for your Jeep Wrangler JL, as well as the modifications required to ensure a smooth, functional upgrade.
1. Understanding Your Jeep’s Trim Level
Before diving into tire sizes and modifications, it’s essential to understand how your Jeep Wrangler’s trim level influences your upgrade. Jeep Wrangler JL models come in several different trims, each with unique features and factory configurations. These trims affect things like suspension height, wheel well clearance, and drivetrain, which are all important when choosing tires.
- Sport & Sport S: These entry-level trims are typically equipped with a stock suspension that can accommodate tires up to 33 inches with a slight suspension lift. Going larger may require suspension and fender adjustments.
- Sahara: A more upscale trim with a basic suspension and better on-road comfort, the Sahara can comfortably fit tires up to 33 inches without extensive modifications.
- Rubicon: The Rubicon is the most off-road-capable trim of the Wrangler JL, they are equipped with an increased factory ride height, 33” tires, locking differentials, lower gear ratio, dis-connectable sway-bar and higher clearance fender flares. Many Rubicon owners can go up to 35 inches or even 37 inches (but further modifications are necessary for the larger tire size). The Rubicon “XR” comes with 35” tires and is a great turn key factory build JL!
- Willys: The Willys trim has some off-road-ready features and pays homage to the rich WWII history that the modern day Wrangler evolved from. It comes with a stock suspension and basic drivetrain. 33” tires can fit with very little modification.
2. Choosing the Right Tire Size
Tire size plays a major role in your Jeep’s overall performance. Larger tires can improve your Jeep’s off-road capability, increase ground clearance, and provide a more aggressive look, but they can also affect ride quality, fuel efficiency, and handling. As a general rule of thumb:
- 33-inch tires: These are a popular upgrade for JL owners, offering improved traction and ground clearance without requiring major modifications. Most trims, including the Sport, Sahara, and Rubicon, can accommodate 33-inch tires with minimal adjustments.
- 35-inch tires: For serious off-road enthusiasts looking to enhance their Jeep’s capabilities, 35-inch tires are a great choice. However, they often require suspension lifts and other modifications, especially for non-Rubicon trims.
- 37-inch tires: These large tires are typically best suited for Rubicon trims or Jeeps that have undergone significant suspension upgrades and high clearance fender flares. Going with 37-inch tires without proper modifications can cause issues with rubbing, handling, and drivetrain performance.
3. Necessary Modifications for Larger Tires
To accommodate a larger tire size, several modifications may be required. Let’s break down the most common upgrades that will help you achieve the perfect fit.
Fender Flares
When upgrading to a larger tire, your fender flares might need to be replaced or trimmed to prevent rubbing against the tires. Options include both stock and aftermarket fender flares in different styles, sizes, materials or those that provide additional clearance. Generally a JL with high clearance fender flares will fit 35” tires with 1”-2” of lift and 37” tires with 2.5-3.5” suspension lift.
Suspension Lift
A suspension lift increases your Jeep’s ride height, giving you more room to fit larger tires. The amount of lift required depends on the tire size you’re planning to install:
- 1.5 to 2-inch lift: Typically enough to fit 33-inch tires on most non-Rubicon trims. 35-inch tires on Jeep equipped with high clearance fender flares.
- 2.5 to 3.5-inch lift: Ideal for fitting 35-inch tires on non Rubicon trims and 37-inch tires on Jeep equipped with high clearance fender flares.
- 4-inch lift or more: Required for fitting 37-inch tires comfortably, or 38-inch + with high clearance fender flares.
Remember, the larger the tire, the more lift you may need to prevent rubbing during articulation and full turning.
Gear Ratio
Upgrading to larger tires can impact your Jeep’s performance, especially its acceleration, towing capacity, and fuel efficiency. The larger the tire, the more strain you place on your drivetrain, particularly the axle and differential gears. You will need to re-gear your Jeep to match the larger tires, which helps maintain the correct balance between power and efficiency. Typically, a gear ratio of 4.10 is ideal for 33-inch tires, 4.56 for 35-inch tires, and 4.88 or 5.13 for 37-inch tires.
Wheel Dimensions (Width and Offset)
In addition to the tires, your Jeep’s wheels also play a key role in ensuring a proper fit. When choosing new wheels for larger tires, consider the following:
- Wheel Width: Wider wheels allow for a larger contact patch with the ground, improving traction, but they also require more clearance. A wheel width of 8.5 to 9.5 inches is common for 33-37 inch tires.
- Wheel Offset & Backspacing: The offset and backspacing determine how far the wheels extend outward from the Jeep’s body. A positive offset can cause rubbing against the fenders, while a negative offset pushes the wheels outward for better clearance. For larger tires, a wheel with around 0 to -12mm offset is often ideal although this depends on exactly what model JL you have. The JL Wrangler has wider axles than any other model and more positive offset can be used successfully.
Spare Tire Carrier
If you’re going with larger tires, you’ll also need a spare tire carrier that can handle the added size and weight. Larger tires, especially 35 inches and beyond, can be too heavy for the stock carrier. Consider upgrading to a heavy-duty spare tire carrier, which may include additional support for your rear tailgate and the mounting system.
Bump Stops
Bump stops prevent your tires from rubbing against the fenders or suspension components when the Jeep is under compression. Larger tires may require longer or additional bump stops to keep your Jeep from damaging the fenders, suspension, or tires during off-road excursions.
Conclusion
Upgrading the tire size on your Jeep Wrangler JL is one of the most rewarding modifications you can make for enhanced off-road performance and visual appeal. However, it’s essential to plan ahead, considering your Jeep’s trim level and the necessary modifications to achieve the ideal fit. Whether you’re aiming for 33-inch tires for daily driving or going all out with 37-inch tires for extreme off-roading, Mount Zion Offroad is here to help guide you through every step of the process.
Ready to take your Jeep Wrangler JL to the next level? Contact Mount Zion Offroad today to schedule a consultation and let us help you choose the best tire size and modifications for your needs.
By optimizing your Jeep for larger tires, you not only boost its capability but also enhance its overall aesthetics and performance. We’re here to make sure that your off-road adventures are as smooth and enjoyable as possible. Reach out to our team today to get started!
Call us at Mount Zion Offroad for expert advice, premium upgrades, and top-notch service!
