During the past 30 years the four-wheel drive community has become accustomed to the tire industry adding a tagline or specific designation to their offerings. In the sports car arena, a “V” rated tire will take you up to 149 mph, while a tire with a “Y” rating will remain structurally sound at speeds of 186 mph. But when we pull off the pavement we are more focused on trail performance, and tires usually assume an all-terrain (AT), or mud-terrain (MT) designation. When General Tire began developing the new Grabber, they took a slightly different approach. Their goal was to create a tire that would redefine the “X” in extreme performance and do so on three distinct terrains: mud, dirt, and rocks—X cubed you might say. I recently spent two days on the trail in the Appalachian Mountains in a Jeep JK Rubicon with the X3, running it through and over its favorite terra firma flavors.
On the Trail
The first “X” we hit was mud. It wasn’t the Southern gumbo that will suck a boot off your foot, but there was enough to get a feel for the X3’s self-clearing properties. It has a fairly wide and deep void pattern, which did a good job of vacating debris when needed. The tread blocks roll off the shoulder and onto the sidewall, and feature variable alternating depths. This allows the sidewall to bite, or scoop mud from the side of a rut. I found the tire was able to not only keep the Jeep moving forward, but also clear the tread block upon reaching dry ground.
Intertwined with the mud sections were areas of dry cross-axle ruts filled with regular old granulated dirt—the type of texture where micro keying plays its hand. The alternating scoops not only help in the mud, but their wraparound design provides excellent bite when climbing out of one rut and into another. Stone bumpers (ribs in the bottom of the tread void) are designed to quickly expel gravel and other debris from the void, thus reducing the grinding affect an embedded rock would have with each revolution of the tire. Molded into the leading edge of each tread lug is a “traction notch,” a wedge-shaped cutout designed to provide lateral grip on sidehill or cambered scenarios.
With the Rubicon Trail in my backyard, and having learned much of my technical driving skills there, a tire’s ability to conform to the terrain and provide excellent dry-surface traction (or wet or snowy) holds a high priority in my book. It must also be able to survive the abuse caused by jagged, immovable edges repeatedly grinding against its sidewall. I am, of course, referring to low air pressure scenarios, which tire manufacturers rarely embrace. This is how tires work best in many terrains, and I was glad to see the General had our X3s at 15 psi.
There is a feeling you get in that lower portion of your back you sit on when your tires are functioning properly in the rocks. They should feel grippy, as if you were dragging your hand across a glue strip (adhesion). When surmounting a boulder or vertical ledge, the tires should absorb the impact (like sticking your finger in a marshmallow) rather than transmitting it through the steering system to the steering wheel. The carcass should deform, allowing the tread lugs to wrap around the terrain (macro mechanical keying) and maximize the footprint. It should not feel like the obstacle is repelling your vehicle like a four-wheeled pogo stick. The sidewall tread should provide traction similar to primary contact surface, and be tough enough to hang the full weight of the vehicle without tearing or chunking. I can summarize in three words how the X3 performed on dry, Rubicon-style granite: They worked great!
On the Road
Although the X3 is designed for the trail less traveled, its on-road manners are reasonably tame. The multi-pitch pattern of the tread blocks is specifically designed to minimize highway noise at speed. Siping is becoming commonplace in the off-pavement tire market, and the X3’s full-depth sipes should enhance wet-surface performance. We didn’t have a chance to give it a proper skidpan, wet pavement, or slalom course test; this will be left for a long-term review.
As technology levels continue to increase, the off-road tire arena is heating up. To hit the mark, General spent 3 years developing the X3. They carefully analyzed more than a dozen tread designs, built and tested 1,000 prototypes, and logged more than 2 million miles before arriving at what they believe is a best-in-class offering. We’ll need to get a set mounted for a 20,000-mile road trip to do a proper evaluation (analyzing tread life, chip resistance, and midlife noise), but my initial impressions are positive. The X3 is expected to hit dealer showrooms in September and will be available in 29 sizes:16 LT metric and 13 flotation sizes ranging from 31 to 37 inches. All incorporate the company’s 3-ply Duragen construction and they will even offer 15-inch sizes for old-school dogs like me. General Tire did their homework and has put their best lug forward with the Grabber X3.
To view all their great products, visit generaltire.com.
Continental TerrainContact A/T
Also to be released in September is Continental’s first all-terrain tire, the TerrainContact A/T. It targets the SUV and light truck markets, and drivers who want reasonable off-pavement traction while sacrificing little on the street. Its tread pattern is more aggressive than a M/S and voids are larger. The TerrainContact also features full-depth sipes and a patented +Silane rubber cocktail that should provide premium all-weather traction and extended tread life (60,000-mile limited tread life warranty). We didn’t get much time on the trail with the new all-terrain, but we did give it a workout on the pavement in Land Rovers and Ford F-250s, as well as emergency braking on a wet skidpad. We made multiple passes at highway speed (55 mph) with the TerrainContact and then with two competitive tires. My personal results were a 5-percent decrease in stopping distance with the TerrainContact. Continental’s new offering could be a good choice for overlanders with a full-size truck and camper, and those who rarely need an aggressive tire such as the Grabber X3.
For more information, visit continentaltire.com