Finding the biting edges of a tread pattern is a tedious process that requires patience an
With our footprint data tabulated, we taped off each tire's contact patch on a new un-mounted fifth tire of each set. Then, we measured out precisely how many biting edges each tread pattern had in its given footprint. We did this using a Scale Master digital plan measuring tool, which is essentially a digital ruler with a little rolling wheel that counts as you move it across a surface. We traced the contour of any tread element in the pattern that touched the glass and featured a biting edge. These included the edges of individual lugs, as well as each side of any type of sipe or tread opening.
Next, we checked the hardness of the compound of each tire using a digital Shore type A durometer gauge tool. This information would tell us how much a specific compound would conform to a given surface. We took measurements in two areas of each tire: the tread and sidewall.
This is a look at what the ground sees when a tire is aired down to 10 psi.
With all the data tabulated, we started the drawn-out road test process. Our route consisted of 100 miles that would provide critical feedback on each set of tires. The loop included rural paved roads, multi-lane asphalt and concrete freeways as well as a few miles of twisty dirt and gravel. We checked each tread's noise level using two individual decibel meters to produce an average sound level per pattern.
Finally, we loaded the pressure washer, floor jack, and air compressor along with all 40 tires in a 16-foot dump trailer and headed out to Hollister Hills SVRA for a day of back-to-back mud-terrain testing. Luckily, the day we did our testing, it was raining all day long. This gave us the opportunity to evaluate each design over a test loop that would easily find the limits of each tread's ability to make traction. The area we used for this testing featured parts of the area we use for the Obstacle Course at Top Truck Challenge. We drove each set of tires up and down the rain-soaked Truck Hill hillclimb, as well as through a two-mile loop featuring one very challenging, rutted off-camber S-turn hill climb with slippery clay mud.
At the end of our mud testing, three tread patterns in particular seemed to overshadow the others. However, as we stated earlier, we believe a mud tire should perform well in all types of terrain. So we had to also consider the data acquired during our 100-mile on-road testing, too. In the end, even we were surprised with the results.
The Tires
(in alphabetical order)
BFGoodrich Mud-Terrain T/A KM2
Goodyear Wrangler MT/R with Kevlar
Hankook Dynapro MT
Maxxis M8060 Trepador
Mickey Thompson Baja MTZ
Nitto Trail Grappler M/T
Pit Bull Rocker LT
Pro Comp Xtreme Mud Terrain
Interco Super Swamper TrXus
Yokohama Geolandar M/T
A durometer is a tool used for testing the hardness of soft rubber products. We tested eac
| Compound Durometer |
|
Tread |
Sidewall |
| BFGoodrich Mud-Terrain T/A KM2 |
66 |
58.5 |
| Goodyear Wrangler MT/R with Kevlar |
71 |
67 |
| Hankook Dynapro MT |
63.5 |
61 |
| Maxxis M8060 Trepador |
72 |
61 |
| Mickey Thompson Baja MTZ |
65 |
55 |
| Nitto Trail Grappler M/T |
66 |
52.5 |
| Pit Bull Rocker LT |
58 |
60 |
| Pro Comp Xtreme Mud Terrain |
66 |
61.5 |
| Super Swamper TrXus |
64.5 |
55 |
| Yokohama Geolandar MT |
69 |
65 |
More About America's Tire
Discount Tire and America's Tire are two unique names for one nationwide company. Discount Tire started in Michigan in 1960 and has since spread its wings from coast to coast, with over 600 retail stores. However, in some regions, other companies already held the name "Discount" in a similar context. In those regions, the name America's Tire was adopted, and any purchase made at any Discount Tire or America's Tire store can be serviced at locations bearing either name. For over 28 years, Discount Tire/America's Tire has offered a very customer-friendly tire replacement program the company refers to as the Certificate for Refund, Repair or Replacement program. Unlike most tire warranty programs, if a tire purchased from Discount or America's Tire should fail due to a defect or an non-repairable road hazard, still has legal tread (3/32 inch) remaining across the tire, and is less than three years old, Discount Tire/America's Tire will give a full refund of the purchase price. They will even give you the option to purchase the same new or comparable tire at the refund price. There is no prorating, no disqualification for any reason, and no mileage adjustment. We think it's the most comprehensive tire certificate program available today. Info: America's Tire, 800/589-6789, www.discounttire.com
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We learned a lot about the different manufacturers' ability to build a tire repeatedly to
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This is the bullet-resistant piece of acrylic glass we purchased from Tap Plastics. We fig
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Keeping track of the test data was as much a priority as photographing the process. Theref