2005 4x4 & Off Road Truck Tire Test - Lugfest

Cooper Tire builds tires for the replacement market, and they are now entering the off-road arena. The company's research shows that truck owners want larger tires, especially those planning on backcountry exploring while hunting, camping, or wheeling. Cooper revealed its new 37x12.5R17LT Discoverer STT radial, and we quickly tracked down a set for testing.

This mud-terrain style is perfect for the outdoorsman looking to replace those dealership skins. We found them excellent in mud, and perfect for getting down muddy rutted two-tracks. With a load D rating we would feel confident towing the horse trailer, hauling hay to the back 40 over slippery lanes, and then loading the camping gear and disappearing for the weekend. We were not impressed with these tires in the rocks, as they had a tendency to slide sideways. However, they were not designed as a rockcrawling tire, rather an all-around 4x4 tire, and they fit that job to a T. Our on-the-road testing did reveal some noise, not the slapping like a Swamper, but rather a high whirring. Where the Discoverer STT really steps ahead of other tires we've tested is the fit and finish. These tires look like they were machined from the rubber rather than molded. Every little notch and tread was perfect, and in the tiny circumference grooves behind the Cooper name, we couldn't find a single glitch. Verdict: perfect for your working, hunting, and exploring rig.

WheelsWe fitted the Discoverer STTs on a set of the new American Racing Moab rims. Reminiscent of the old Ansen slot-style rims (same as those found on the Starsky and Hutch Torino, considered by my uncles as the best-looking truck wheels), these forged-aluminum wheels are just the tip of the iceberg of American Racing's new ATX series of forged wheels. The Moabs are available in 17x8-, 10-, and 12-inch sizes, with 411/42-inch backspacing and all the major bolt patterns.

Pit Bull RockerPit Bull Tires just showed up, ready to tear into the off-road tire scene. Pit Bull has been growing since its start in 1994 as a subsidiary of Tire Mart Inc., a wholesale tire company with over 65 years of experience. Pit Bull was started to provide tires for off-road motorsports, and has been involved in CORR racing and both the National and American Tractor Puller Association, so the release of its three off-road tires-the Rocker, Maddog M/T, and Growler All Terrain Extra-comes from a background in the dirt.

We quickly rounded up a set of 35-inch Rocker treads and bolted them onto a set of Rockcrusher RT bead locks from Allied Wheel. The cast wheels look awesome, but we struggled a bit getting them mounted. As for the tires, these things look like they are straight out of a cartoon, and the tread makes no sense to us. We think the tire engineers put the shape of every state in the nation in the tread; we saw Texas, California, New York, Florida, and West Virginia. But looks don't mean anything if the tire works, and in the rocks these Rockers work. The Pit Bulls are noisy on the street... very noisy, but if you are getting these to run on the street, then you're probably the type of person that likes the roar of a beefy tire. We found that when aired to 30 psi, the tires got a serious crown to them and it seemed that only the center of the tread was touching the asphalt. Very odd, but hey, these weren't designed to commute, they were designed to wheel.

Maxxis Creepy CrawlerWhen you visit the Maxxis Tire Web site you can choose between the following: ATV, Industrial, Bicycle, Lawn and Garden, Cart, Motorcycle, Trailer, and Truck/Automotive tires, so it goes without saying that Maxxis has some experience in the tire world. Even so, we were surprised with the results we got from the Maxxis Creepy Crawler bias-ply tires we tested. We went with a set of 37x14.50-16LT, and mounted them on some cast Center Line Cooler aluminum rims.

These tires look very aggressive with extremely deep tread voids and some of the tallest sidewall tread we've seen. This helped them climb like crazy on the rocks, and we were truly amazed at how quiet they were on the asphalt. They were literally as quiet as some of the all-terrains we've tested. In the mud they did respectable as would be expected from the tall treads. They were a bit squishy on the road, but once we got to the off-camber turn in the rocks, they literally stuck the line and didn't slip at all. The name is correct, a true creepy crawler.

Interco, Toyo, & BfgoodrichWe've been testing, abusing, and generally beating a few other tires here and there, and though most of these are not brand new, we do have some new sizes to tell you about, as well as some new insight on the tires we've been testing.

Pro Comp Xtreme A/TWe will be leaving these Pro Comp Xtreme A/T tires on our Avalanche for a while, not because they are the most extreme tires or because they can dig through mud like a tractor. No, we'll be leaving them on the Avy 'cause it's now becoming more tow rig and daily-driven work truck than trail machine, and these are the type of tires you put on a tow rig and forget about. We know we are giving up some of the gnarly trail-tire appeal by going to this rubber, and if we indeed were going to run some serious rock or mud with the big beast we would probably change shoes, but, the Avy spends more time running for parts and hauling camping gear. As we head to cover events or wrench on project vehicles, these quiet-yet still capable-all-terrain tires are the perfect compromise.

We usually steer clear of all-terrain tires like the pink shirts our publisher wears, but a friend started touting his Pro Comp all-terrains after returning from a long trip to Baja, and when we saw these 37x12.50R17s under the black Chevy Dualie we feature elsewhere in this issue, we decided to give them a shot. We thought we had ordered a set with black rims, but when these came mounted on chrome steelies, we quickly decided that our olive-drab project Army truck wasn't gonna get them, but rather the Avalanche. Another thing that we only noticed as we were getting ready to mount them on the truck is that these tires are directional. We've never seen an all-terrain that is directional before, and it's only the outer lugs that seem different, so we have a feeling it's a trickle down from the knowledge Pro Comp learned with its directional Xterrain rockcrawling tires.

Mickey Thompson Baja ATZMickey Thompson is a name renowned in the tire business, and while its new Baja ATZ is a solid contender in the all-terrain tire field, it's not the one you want in a muddy field.

We mounted a set on our Project Jeep XJ and took them out on a rainy day to see what type of trouble we could get in, and it didn't take long. We definitely like these tires for street cruising, and we were even impressed with their performance on rocks (wet rocks didn't even stop them), but for the mud we will wait for the Baja MTZ in less than bling sizes, or better yet, the as-yet-unseen Baja Crusher.