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Massive Mud Tire Shootout: Intro

Jeep Wrangler Jk Test Mule
Robin Stover | Writer
Posted April 1, 2011
Photographers: Cody Kanuscak

Ten-Tread Battle Royal

Mud tires are about as varied as the flavor combinations at a big-chain coffee shop. However, unlike the jittery effects of triple-strength latté, a good mud tire will return ample traction where it matters most, and then transition smoothly to the next task you throw at it. A tire's ability to propel a vehicle in deep mud boils down to three key factors: tread and sidewall design, carcass flexibility, and compound. Each of these factors can have good or bad effects on a tire's performance in other types of terrain. What might be awesome in deep gooey mud might be absolutely a nightmare on the street, and vice versa. We believe a good mud-terrain tire should perform well in all versions of terra firma; after all, mud only happens when dirt and water mix. The rest of the time, you have dirt, rock, sand, and snow-not to mention all forms of pavement.

With this test, we set out to evaluate ten popular mud tires in an assortment of real-world driving scenarios. The idea was to mimic what the average 4x4 enthusiast, who drives his or her vehicle daily, might encounter in any given month. We wanted to see how each of the three variables listed above affect total tire performance. We picked a 37x12.50R17 because it is one of the most popular sizes used on lifted vehicles today. As such, our results are not geared towards competitive mud boggers, or trailer queens that rarely touch the pavement. We set up this shootout for the average wheeler who, like us, uses his or her primary vehicle for all aspects of life, from navigating backcountry trails to retrieving a cup of Joe at the local strip mall. With that in mind, the rankings on the pages that follow should be considered in terms of the tires' overall performance, both on- and off-pavement, and not solely construed to performance in mud. Also, we realize that there are many different types of mud around the country, so our impressions are based only on the kind of mud we encountered at our northern California test facility. As the old saying goes, your mileage (and your mud) may vary.

The Testing
To conduct an apples-to-apples comparison on 10 different tire brands, we needed to eliminate any potential for variables. First, we weighed each tire to ensure against manufacturing anomalies. We wanted to see how close each tire was to the manufacturer's published weight specification. This process was eye-opening, to say the least. Some were precisely in spec, while others were as much as 11 pounds over the published weight. Next, we secured 40 identical Classic II 17x9-inch aluminum wheels from Mickey Thompson. We had each wheel balanced without tires attached to ensure that any manufacturing variances would not affect our tire balancing results. We enlisted the help of the professionals at America's Tire in Salinas, California, to make this happen. As timing would have it, the folks at America's Tire had their monthly calibration service performed on the morning our tires and wheels arrived. We think balance-ability is a key factor of a quality tire, especially when you are talking about large and heavy mud tires. Achieving perfect balance is critical to the life of drivetrain components such as bearings, seals and the tires themselves. The better a tire is from the start, the easier it is to balance, and the more likely it will remain in balance while in use. Balance also says a lot about a tire manufacturer's ability to build a consistent product-something all tire companies strive for.

Once all tires and wheels were mounted and balanced, we took them back to our Northern California evaluation lab to conduct a barrage of assessments. We filled each tire to 35 psi and measured the static ride height. We were surprised to find that just one brand, Goodyear, measured over 37 inches tall. All others were just under the 37-inch mark.

Next, we lowered each set of tires to 10 psi and mounted them, one set at a time, to our JK test mule. We parked the Jeep on top of a 20-foot flatbed gooseneck trailer that we modified to quantify each tire's interface with the ground.

To achieve this, we ordered a 24x18-inch piece of bullet-resistant acrylic glass from Tap Plastics in Stockton, California. We surrounded the 11/4-inch-thick acrylic sheet with a TIG-welded stainless-steel frame to help stiffen it under the load of the vehicle. We cut a hole in the wooden deck of the trailer and positioned the glass flush with the deck surface. This would allow us the opportunity to see what the ground sees when the weight of the vehicle is upon it. We took pictures of each tread pattern from below and, using sheets of white paper, isolated the part of each tread pattern that actually touched the glass. We found that every contact patch had a slightly different shape. We took measurements of each tire's footprint and calculated the total footprint area in square inches.

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