First Roll Review: Goodyear MT/R with Kevlar Off-Road Tires
Words and photos by Mike Levine
What makes an off-road tire good? According to Goodyear’s research with off-road enthusiasts, the two most important things are: not getting stuck and not getting a puncture. If you’re going to get dirty in the wilderness, it better not be from having to fix a flat. To that end, they’ve developed the first all-new Wrangler MT/R (Maximum Traction/Reinforced) off-road tire in a decade.
In designing and engineering the new MT/R tires to excel in the most primitive of off-road conditions, Goodyear partnered with some of the brainiest scientists on the planet.
At Sandia National Labs, Goodyear borrowed time on the same supercomputers that have helped design key components of the U.S. nuclear arsenal to virtually model the real-time interaction of more than 25 different tire components as a tire rolls on and off the pavement. They also digitally modeled various candidate tread patterns, seeking the right balance of rock crawling grip with the ability to quickly flush mud out of the tire’s deep grooves, without needing to travel to Moab or the Louisiana bayou to repeatedly test prototypes.
“We wanted to innovate more quickly,” said Joey Viselli, brand director of Goodyear North America. “We’re the only tire company in the world that’s allowed to work with Sandia. They help us model our tires so we don’t have to keep building and testing (in the real world). It compresses our test time dramatically and (Sandia) can verify their models are accurate because the finished product that comes out the other is extensively tested by both of us.”
The chemical wizards at DuPont helped Goodyear ditch the old polyester sidewall bolstering and make the switch to Kevlar – the same Kevlar used in bulletproof vests – for 35 percent better puncture resistance than the old MT/Rs. Kevlar, pound for pound, is five times stronger than steel. It’s the first time Goodyear has used Kevlar in an off-road tire, the company said.
According to Viselli, Goodyear is the only tire company licensed to use the Kevlar brand in its tire names. Other companies that weave Kevlar into their rolling stock have to use its generic molecular name, aramid.
Goodyear and DuPont also attempted to set the bar higher than Kevlar during their joint research and development.
“Enthusiasts said sidewall strength was critical,” said James Niedermier, lead engineer for the Goodyear Wrangler MT/R with Kevlar. “DuPont supplied us with some very exotic materials and polymers to try and meet our strength requirements, which may have future applications way down the road, but Kevlar worked best.”
Even with the extra computing horsepower and materials assistance, the new MT/Rs still took more than two years to develop. “That’s much more time than a passenger car tire,” Niedermier said.
Melissa Montisano, Goodyear’s general manager for light truck and SUV tires, said about 10 percent of the MT/R tires will be for purpose-built, core off-road applications, like custom rock crawlers or pre-runners. Jeep enthusiasts are expected to purchase approximately 30 percent, for models like the two-door Wrangler and four-door Wrangler Unlimited.
“Pickup trucks are expected to be about 20 percent of the product range,” said Montisano. “They’ll be used for both work and recreational applications. During the week (truck owners) can use their truck for work and on the weekends they can go off-road. These tires are also very good for mining and forestry applications because they’re so robust. The original MT/R has been prevalent in those types of applications because of its heavy-duty construction. We anticipate the same will happen with the new (MT/R with Kevlar) tires.”
The remaining 40 percent, according to Montisano, will be split among other light truck and SUV on- and off-road applications.
Goodyear let us try out the new MT/R with Kevlar tires on Jeep Wrangler Rubicons in Johnson Valley, Calif., which is about an hour north of Palm Springs. Our test vehicle was equipped with size LT285/70R17 load range D rubber.
For those new to reading shorthand tire specs, LT refers to “Light Truck”, 285 is the tire’s width in millimeters (11.22 inches), 70 is the percent sidewall height relative to tire width from rim to tread (199.5 mm / 7.85 in), R identifies that it is a radial construction, 17 is the rim size in inches and load range D describes sidewall strength and the ability to manage air pressure (up to 65 psi max).
The new MT/Rs look impressive and technically sophisticated. The asymmetrical, deep tread pattern across the bottoms combined with sharply carved sidewalls appears ready to claw over or through dirt, sand, rocks and mud while standing still.
As rugged as the MT/Rs appear, they were surprisingly quiet driving to Johnson Valley on surface streets and highways while aired up to approximately 35 psi, even with the prominent wraparound side treads. They lacked much of the road noise and whine that typically accompanies mud terrain tires.
Our day-long testing exercise took us over every major off-road surface type: fine and coarse-grained sand, Moab-like granite rock faces, suitcase-sized boulder strewn dry creeks, hard-packed dry lakebeds and taffy-like mud.
The Jeep Wrangler Rubicons we drove were equipped with on-the-fly locking front and rear differentials and front sway bar disconnect for maximum off-road articulation. The powerplant was a 3.8-liter V-6 engine rated at 202 horsepower and 237 pounds-feet of torque with a four-speed automatic transmission. In order to get maximum traction, we deflated the tires down to 12 psi.
It’s difficult to say exactly where the Jeep’s mechanical capabilities were significantly enhanced or superseded by the strength and gripping capabilities of the Wrangler MT/Rs. What we did notice was that in areas where constant momentum was needed to avoid getting bogged down – in deep mud and in sand dunes – the Jeeps performed amazingly well, staying true to the intended path we wanted to carve. In 4-Hi and 4-Lo, without using lockers, the tires were able to quickly clear dry and wet debris to keep chomping away for grip, so we didn’t find ourselves skidding across the desert like a hydroplaning car on a rain-soaked highway.
After driving through deep mud, we hopped out of the Jeeps to examine the tires’ self-cleaning capabilities. The deep tread was amazingly clear of mud after driving less than 100-yards on hard packed lake bed at speeds below 25 mph.
For rock crawling, we appreciated the high degree of grip the tires provided as they deformed to hug the rocks when most of the Jeep’s weight was balanced on the sidewalls. There was no slip when the Jeep was stationary and little slip as the trucks made progress over the dry stream bed boulder field; helpful for minimizing the unexpected movement of the rocks as the Jeep’s weight shifted climbing over them. They also easily withstood the jabs of the sharp edged granite though the points left noticeable marks and scratches on the Kevlar reinforced sidewalls.
Sand driving was easy, as long as forward momentum was maintained with liberal use of the accelerator through the deep, loose dunes. The sidewall treads again played a critical role helping to optimize traction.
Perhaps the best measure of how well Goodyear has done creating the new Wrangler MT/R with Kevlar was the lack of a single tire failure among the 20 Jeeps in our group through 15 miles of intense wheeling. That’s 1,200 miles ( 4 tires x 20 Jeeps x 15 miles) of off-road tire testing. In fact, the only bummer of the day was a Jeep that overheated from too much mud caking up its radiator.
The new Wrangler MT/R with Kevlar will be available in March in 30 sizes, Goodyear says, including a new 42-inch tall version aimed at the most hard core rock hounds. Goodyear leaves pricing to its retailers but marketing manager Montisano said standard-application tires are expected to cost from $170 to $380 and enthusiast application tires should run from $300 to $550 per tire.
Overall, we’re pretty impressed with the new MT/R with Kevlar. Goodyear hasn’t reinvented the wheel but they definitely have advanced the off-road tire.
