Photography by Harry Wagner
The Jeep Wrangler is the most capable vehicle made, with solid axles, body-on-frame construction, and enough aftermarket options to fulfill any fantasy. From the factory though there is room for improvement, particularly if you start with a Sport or Sahara model. You probably already know that the Rubicon is more capable than the Sport, with the addition of locking differentials, a 4:1 transfer case, and an electronic disconnecting sway bar. While those hard parts are the obvious differences, there are some more subtle differences as well. The Rubicon comes with LT285/70R17 BFGoodrich All-Terrain KO2 tires, while the Wrangler Sport comes shod with 245/75R17 All-Season. Not only is this a smaller diameter tires with a tame tread pattern, but they are also a P-Metric tire. Know what the P stands for? Passenger. These are passenger car tires.
Tread depth of stock Wrangler Sport All-Season tires is 10/32nds of an inch when new. By contrast, the tread on Mickey Thompson’s Baja Boss LT tires is 19/32nds deep. LT tires provide both longer tread life and increased traction off road.
Advantages of P Metric Tires
Jeep has a reason for doing this. P-Metric tires are lighter and have less rolling resistance than LT (Light Truck) tires, and as such they provide better fuel economy. When trying to meet Corporate Average Fuel Economy (CAFÉ) standards for a vehicle that is shaped like a brick, every little bit helps. And honestly, we would much rather they put tame treads on the Wrangler than lower it to the ground or replace the solid front axle with independent front suspension. That isn’t much of a consolation though if you get a flat in the middle of nowhere. Fortunately, tires are a lot easier to add to a truck than an electronic disconnecting sway bar.
The three-ply sidewall construction Nitto uses in their Terra Grappler, Trail Grappler, Ridge Grappler, and Mud Grappler tires is far stronger than the two-ply sidewalls found on P-Metric tires. The stiffer sidewall translates to improved handling, increased resistance to punctures and bruising, and higher load carrying capacity.
Advantages of Light Truck Tires
The huge wheel wells on the JL Wrangler make it easy to fit larger tires without any suspension modifications, even on the Sport and Sahara models. A larger diameter tire will increase ground clearance and make rocks, ruts, and obstacles effectively smaller relative to the size of the tire. But even if you stick with the stock 245/75R17 diameter, there are advantages to running an LT tire in an All-Terrain or Mud-Terrain flavor. Increased traction is the obvious answer, but these tires also use significantly stronger construction. This means that they are less prone to punctures on the trail, and they can carry heavier loads on the road without concerns about overheating the tire’s carcass.
The load rating of the factory tires is 2469 pounds at a maximum inflation pressure of 44 psi. In comparison, these LT305/60R17 Pro Comp Xtreme MT2s are rated at 3195 pounds at a maximum inflation pressure of 65 psi, over 500 pounds more carrying capacity per tire. These far exceed the GVWR of a JL Wrangler.
Which Is Right For You?
Of course, there is no such thing as a free lunch. Those larger, more aggressive tires weigh up to 40% more than the factory tires (the factory tires weigh 32 pounds each, while the same size Nitto Terra Grappler G2 weighs 46 pounds). The added weight has had a modest effect on acceleration and braking, and a more significant effect on fuel economy. Personally, we will trade a few miles per gallon for stronger tires that offer increased traction, require zero modifications to our truck, and give us peace of mind on the trail. As the saying goes though, your mileage may vary.
All of that increase in strength does come at a heavy cost (pun intended). This Baja MTZ P3s weighs a whopping 19 pounds more each when compared to the factory tires. That added weight resulted in a two mile per gallon decrease in mileage on our JL. Going further costs money, how far do you want to go?
4 Wheel Parts carries a wide selection of tire brands, styles, and sizes to fit your vehicle whether it is stock or modified. Tires that are stock size, or close to stock, typically will fit on the factory wheels. The more you vary from the stock size though the more likely you will need wheels with a different width and backspacing.
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