Choosing the right tire size for a Jeep Wrangler JL or Gladiator JT can change how the vehicle looks and drives. There are many sizes to consider, from stock tires meant for daily driving to larger off-road tires that need extra space and can handle rough trails better. It helps to know how tire measurements work, as sizes often appear in standard and metric forms.
Upgrading to bigger tires can make a Jeep look more aggressive and improve its performance off-road. Still, drivers need to think about how changes in tire size might affect things like handling, clearance, and the need for suspension or wheel modifications. Understanding these factors helps people pick the best tires for their needs.
Key Takeaways
- Tire size affects the look and performance of a Jeep.
- Larger tires may require changes to suspension or wheels.
- Knowing how sizes are measured makes choosing a tire easier.
How Tire Sizes Are Measured
Breaking Down Standard Tire Sizes
Standard tire sizes are usually talked about most around Wranglers. These sizes look something like “37 x 12.50” or “33 x 12.50”.
- The first number is the height, or the diameter of the tire in inches.
- The second number is the width of the tire in inches.
- The third number (if mentioned) is the wheel diameter the tire fits, also in inches.
Example Table:
| Tire Size | Height (inches) | Width (inches) | Wheel Diameter (inches) |
|---|---|---|---|
| 33 x 12.50 R17 | 33 | 12.50 | 17 |
| 35 x 12.50 R18 | 35 | 12.50 | 18 |
| 37 x 13.50 R17 | 37 | 13.50 | 17 |
This method is clear and tells you exactly how big the tire is.
Understanding Metric Tire Size Codes
Metric tire sizes appear in a format like “245/75R17”. Each number stands for something important:
- The first number (like 245) is the width of the tire in millimeters.
- The second number (like 75) is the sidewall height, shown as a percentage of the tire’s width.
- The third number (like 17) is the wheel diameter in inches.
Example Table:
| Tire Size | Width (mm) | Sidewall (% of width) | Wheel Diameter (inches) |
|---|---|---|---|
| 245/75R17 | 245 | 75 | 17 |
| 285/70R17 | 285 | 70 | 17 |
| 315/70R17 | 315 | 70 | 17 |
This type of sizing is common for original equipment tires on SUVs and crossovers, not just Jeeps. The key is knowing how to read these numbers so you can compare them or choose a new set that fits your needs.
Advantages of Bigger Tires
Upgrading to larger tires offers a few key benefits, especially for vehicles like the Jeep Wrangler and Gladiator:
- Improved Appearance: Bigger tires give the vehicle a more rugged and aggressive look, which many people find appealing.
- Better Off-Road Performance: Larger tires can handle rougher ground and obstacles more easily. They also raise the vehicle higher off the ground, which helps with ground clearance when driving over rocks or through mud.
- Enhanced Traction: Choosing all-terrain or mud-terrain tires in larger sizes usually means better grip in dirt, sand, and snow.
- Custom Fit Options: There is a wide variety of tire sizes and types available. This allows for matching tires more specifically to the type of driving—for example, choosing mud-terrain tires for more off-road use.
| Tire Size Example | Type | Benefit |
|---|---|---|
| 33-inch | Mud Terrain | More traction and ground clearance off-road |
| 35-inch | All Terrain | Even larger footprint for handling obstacles |
| 37-inch | Mud/All Terrain | Maximum height and aggressive appearance |
Note: Larger tires may require extra modifications, like changes to the suspension or wheels, for proper clearance and to avoid rubbing when turning.
Tire Choices for Jeep Wrangler JL and Gladiator JT
Standard Factory All-Season Tire Types
Factory tires on the Jeep Wrangler JL and Gladiator JT are usually all-season tires. These are designed for use on roads throughout the year, handling dry, wet, and light snowy conditions. Most factory all-season tires are suitable for daily driving but do not perform well off-road.
| Tire Example | Size (Metric) | Approx. Diameter | Best Use |
|---|---|---|---|
| Stock All-Season | 245/75R17 | 31.5 inches | On-road, year-round |
All-season tires fit most SUV and crossover needs. However, for drivers who want better off-road capabilities, these may not be the best choice.
Moving Up to All-Terrain Tires
All-terrain tires are a popular upgrade for Wrangler JL and Gladiator JT owners. They come in sizes close to the originals but use tougher tread and sidewall designs. All-terrain options, like the 265/70R17, offer improved grip on a variety of surfaces, including mud, sand, and snow.
Advantages of All-Terrain Tires:
- Works well both on-road and off-road
- Handles different weather and terrain types
- Maintains comfort and road manners
Example Option:
- Nitto Terra Grappler G2, 265/70R17 (about 31.5 inches tall)
- Great pick for occasional trail use while keeping on-road performance
Benefits of Mud Performance Tires
Mud tires are designed for drivers who travel off the pavement more often. These have aggressive tread patterns meant to boost traction on muddy and rocky ground. For example, moving to a 285/70R17 mud tire means a tire about 33 inches tall and 11 inches wide.
Mud Tire Features:
- Larger tread blocks
- Deeper channels for self-cleaning
- Increased ground clearance
Example Option:
- Falken Wildpeak Mud-Terrain, 285/70R17
- Best for regular off-roading and rough terrain
Mud tires can still be used on the road, but they are noisier and may wear out faster on paved surfaces compared to all-terrain options. These are ideal for those looking for better performance on rocky, muddy trails.
Tire Size Progression and Fitment
Factory Tire Setup
From the factory, the Jeep Wrangler JL and Gladiator JT often come with all-season tires. These usually have a metric size like 245/75R17. This kind of tire provides good year-round performance in different weather, but is mostly made for driving on roads.
Quick Reference Table
| Typical Factory Tire | Size | Features |
|---|---|---|
| All-Season | 245/75R17 | Good on pavement, usable year-round |
| Stock All-Terrain | 265/70R17 | Slightly better for off-roading |
Key Points for 33-Inch Tires
A 33-inch tire, such as a 285/70R17, is a popular step up. This tire is taller and a bit wider than stock. Many Rubicon models can fit this size on the factory wheels with no extra upgrades.
- Better off-road grip: 33-inch mud-terrain tires give more traction in mud, snow, and over rocks.
- Stock wheels friendly: No need for new wheels on some models.
- Minimal changes: Costs stay low since fender or suspension upgrades are usually not needed for Rubicon models.
Upgrading to 35-Inch Options
Moving to 35-inch tires like 315/70R17 brings more ground clearance and a wider tread. This lets the Jeep handle tougher trails and bigger obstacles.
- Suspension lift suggested: Most non-Rubicon trims will need a suspension upgrade, or at least new fender flares.
- Wider tires: These tires may need either wheel spacers or aftermarket wheels with less backspacing to avoid rubbing.
- Heavier tire: The increase in size adds weight, which can slow acceleration and lengthen braking distances.
Stepping Up to 37-Inch Configurations
A true 37-inch tire, such as a 37×12.50R17, needs more planning.
- Suspension required: Owners usually install a lift kit (for example, 2.5-inch suspension lift) to make enough room.
- Aftermarket wheels: It is often needed to run wheels with the right offset for proper clearance.
- Greater clearance: These tires improve off-road ability, but require more changes to the Jeep to work safely and properly.
Considerations With 40-Inch Tires
Fitting 40-inch tires calls for major changes.
- Extensive upgrades: Larger suspension lifts, custom wheels, and even axle and drivetrain changes may be necessary.
- Heavy weight: This much larger tire puts extra stress on steering, brakes, and drivetrain parts.
- Special use: Most people only run 40-inch tires if their Jeep is a dedicated off-road rig.
| Tire Size | Typical Width | Wheel Size | Suspension Needed | Wheel Mods Needed | Notes |
|---|---|---|---|---|---|
| Stock | 9.5–10.5″ | 17″ | No | No | Best for daily use and light off-roading |
| 33″ | 11″ | 17″ | No (Rubicon) | No (Rubicon) | Good mix of looks and off-road ability |
| 35″ | 11–11.5″ | 17″ | Yes (most cases) | Yes | Bigger lift and stronger components needed |
| 37″ | 12.5″ | 17″ | Yes | Yes | Major upgrades required |
| 40″ | 13.5″+ | 17″+ | Yes (Large) | Yes | Only for heavy off-road use |
Changes to Suspension and Increased Ground Clearance
Adjusting Fender Flares for More Room
When considering a bigger tire, not all fender flares give the same amount of space. The Rubicon’s stock fender flares come set higher than those on Sport or Sahara models. This extra height makes it easier to fit larger tires without them rubbing. If bigger tires are needed on non-Rubicon models, swapping out for higher flares or modifying the fender setup becomes important.
Main reasons to adjust fender flares:
- More clearance for larger tires
- Helps prevent rubbing while turning or off-roading
| Model | Fender Flare Height | Bigger Tire Fit? |
|---|---|---|
| Rubicon | Higher | Yes, fits larger tires |
| Sport/Sahara | Lower | May need upgrades |
Things to Know Before Raising Suspension
Putting on a suspension lift is important with bigger tires, especially above 33 inches. For example, a 2.5-inch lift is often added when moving to 35-inch or 37-inch tires. This not only creates space for the tire but also lets the axle move freely when dealing with rocks or uneven ground.
Points to think about:
- Lift kits give more room between the wheel and fender
- Helps the tires clear obstacles when off-roading
- Needed for wider tires on Sport/Sahara/Overland trims
A proper lift helps avoid problems like the tires rubbing on the body or getting stuck when the suspension flexes.
Moving Tires Out With Wheel Spacers and Changing Backspacing
Large or wider tires might hit parts inside the wheel well. Wheel spacers are a common fix—they push the wheel outward, which helps avoid rubbing when turning. Aftermarket wheels with less backspacing also move the tire farther out from the hub, creating the extra space needed for bigger tires.
Ways to create more room for tires:
- Install wheel spacers
- Choose wheels with lower backspacing
Both methods help fit wider tires and keep steering smooth. This is especially useful for 35-inch tires and above.
Note: Whenever using wider tires, these adjustments help cut down on unwanted friction and keep the vehicle safe and comfortable to drive.
How Tire Size Affects Vehicle Performance
Changes in Maneuvering and Trail Ability
A larger tire gives a Jeep more ground clearance, which helps it get over rocks or rough trails. Wider tires can also improve grip, especially in mud or sand. Stock-sized tires work fine for everyday roads, but larger tires offer better performance off the pavement.
Comparison Table:
| Tire Size | Terrain Handling | Off-Road Capability |
|---|---|---|
| Stock | Good for roads | Basic |
| 33-inch | Improved | Better |
| 35-inch | Better | Great |
| 37-inch+ | Best | Excellent |
A bigger or wider tire might need changes like new wheels or spacers so it does not rub when turning. Suspension lifts can also help by giving the tire more room to move.
Acceleration and Stopping Changes
As tire size increases, the tires get heavier. This extra weight means the vehicle takes more power to speed up and takes longer to stop. Drivers will feel that the Jeep is a bit slower off the line and can take more distance to come to a full stop.
Key points:
- Bigger tires can slow down acceleration.
- Brakes will need more time and distance to stop the vehicle.
- Each step up in tire size makes these changes more noticeable.
All of this means that, while large tires look great and work better off-road, they also change how the Jeep drives on the road, especially when it comes to speeding up and slowing down.