Getting Dirty With The Cooper Discoverer STT Pro
Tires are one of the most important upgrades you can make to improve the off-road performance of your vehicle, and mud terrains are some of the best tires for improved traction in any terrain. Cooper recently introduced the most aggressive tire in their light truck lineup, the Discoverer STT Pro M/T, so we promptly threw on our Ford F-250 daily driver weekend-wheeler to see how they would handle every day use.
The STT PRO is Cooper’s replacement for the departing, but very popular, Discoverer STT. The STT PRO gets its strength from a three-ply sidewall that features the company’s proprietary Armor-Tek3 protective ply. This ply in the sidewall runs 90 degrees to the first two giving the tire a tremendous amount of strength and increased sidewall puncture resistance, perfect for those pesky sharp branches that seem to always find their way to the sidewall. Since tire and wheel damage are always a possibility while off-road, the STT PRO has a Rubber Rim Flange Protector that is built into the tire along the lower sidewall that protects the wheel and tire from damage while wheeling.
While the STT Pro is designed to conquer mud, it packs plenty of features that are great for all types of terrain. The tread pattern of the STT PRO is one of its most impressive features. The tread pattern is a hybrid design featuring a 3-2 inner tread rib pattern that works to reduce road noise while improving off-road traction. With Mud Release Dimples (small dimples that run along the shoulder tread that create air pockets that release mud), as well as Mud Scoops and Scallops, the STT PRO can claw its way through even the stickiest mud while cleaning itself out.
Since airing down tires for wheeling is a common occurrence when off-road, the STT Pro has that covered as well. Side Biter Cleats and a Flex Groove aid in performance the air pressure is low. The Side Biter Cleats give improved traction when the sidewall is against an obstacle, and the Flex Groove is a designed flex point that improves performance by damping uneven surfaces.
These tires were designed for traction in all terrains, even water. The tire is built with Silica-infused rubber compound that provides excellent traction and even improves cut and chip resistance. Braking distance is also improved thanks to this hi-tech silica compound.
With a set of 37x13.50R18s mounted Black Rhino Tanay wheels we put some miles on these mud terrains, and we were impressed. From the highway to the dirt, the STT Pro delivered in every aspect. In the mud, the tires gave you a stable feeling even when it was thick and sticky. When climbing rocks the large lugs and Side Biters bit hard and failed to slip. In loose soil the tire scooped their way to traction and where even capable in sand. On the highway they did make noise, but not to the point you couldn’t still have a conversation.
We were thoroughly impressed with the new STT PRO from Cooper, and after 5,000 miles of highway/trail driving the tread still looks brand new even on our 8,000-pound truck. These tires give us the confidence to take on any obstacle even in the sloppiest of terrain.
Even after a lengthy trip trough a deep, sticky, muddy trail the tread is fairly clean without even hitting hard pack.
The Mud Release Dimples paly a key role in cleaning the tread blocks out, you can see them on the outside of the outer tread block.
Even in damp sand, the wide footprint and self-clearing tread blocks the STT PROs provide excellent traction without packing the tire.
Wrapped around our 18-inch Black Rhino wheels, the large sidewall provides plenty of flex for a wide footprint in soft terrain and the ability to couture to larger obstacles with ease.
Size Tested: 37x13.50R17
Load Range: D
Maximum Load (lb): 3,525
Sidewall Plies: 3 w/Armor-Tek Protective Ply
Approved Rim Width (in): 8.5-11
Tread Depth (in): 22/32
Section Width (in): 13.3
Overall Diameter (in): 36.77
Test Vehicle: ’11 Ford F-250