It didn’t take me very long to learn how to tell a brown trout from a rainbow or brookie. And I easily mastered the differences between a pumpkinseed and a bluegill. But when confronted with the redear, redbreast, or longear sunfish, things got a good deal more complicated. Even now, I occasionally consult a field guide to be sure.
So it is with tires for a 4×4. With so many designs available, how can you identify the correct tire for your pickup or sport utility? Consulting the simplified “field guide” below can make things easier. Use it to narrow the choice to a particular type of tire. Then go to a dealer for information on the specific model within tat tire type.
Essentially, there are four types of tires of concern to outdoorsmen: 1) highway rib; 2) highway/all-season; 3) offroad/all-terrain; and 4) maximum traction offroad.
1) Highway-rib tires usually have a four-or five-rib design. (A rib is the standing tread that circles the tire.) Each rib is siped, which means the ribs have little slahes that help provide biting edges for traction in dirt, slush, and snow.Their design provides good, even wear, low noise levels, and a smooth ride. These tires often have low rolling resistance that helps increase fuel economy.
Highway rib tires usually have a four- or five-rib design. Each rib is siped, which means the ribs have little slashes that help provide biting edges for dirt, slush, and snow traction. The grooves between the ribs can be jagged to provide even more of a bite. The shoulders (the inner and outer ribs) are wider to help cornering and braking performance. These tires are designed primarily for highway use, but will perform adequately in light to moderate snow and on level gravel and dirt roads.
2) The highway/all-season tire maintains the rib-type look, but the ribs now consist of small, independent blocks positioned around the tire, which help it deliver greater performance in dirt and rain. The zigzag sipes in the blocks also help traction on snow and ice. This type of tire is an evolutionary step up from the tire profiled above. The more aggressive tread design helps it better deal with dirt and snow, so that as loose dirt and snow are compressed into the openings, you actually end up with more traction. At the same time, the rib-type design helps the tire maintain on-road performance very close to that of a highway-rib tire. The highway/all-season tire works well on dirt roads, gravel roads, sand, and in moderate snow.
3) The offroad/all-terrain tire has as much capability on the road as it does off the road. The tire features an interlocking tread design, which means that before the leading tread block leaves the ground, the following tread block has already come into contact with it. This allows the individual blocks to work together to help maintain ride quality and promote even wear. In addition, the multi-faceted tread blocks help deliver traction from any direction on dirt, sand, and gravel; provide handling, acceleration, and stopping ability in order to avoid a rock or a stump; and help the vehicle negotiate other obstacles. The lugs on the shoulder of the tire and the pockets between each lug foster good offroad steering response and traction. This is a tire for dirt trails, rocky trails, shallow mud, and moderate to heavy snow, yet it remains fairly civilized for highway use.
4) As the designation suggests, the maximum traction offroad tire is focused mainly on offroad travel. Nonetheless, the newest designs are acceptably refined for highway travel. Notice that the interlocking tread design now features large, free-standing blocks. Also, the siping has been replaced by large gaps. The goal of this tire is to bite into loose or muddy surface areas for maximum traction and propel the vehicle forward. The very large opening between the lugs helps make the tire self-cleaning: the mud is compressed as the tire gets a grip and then expelled as the tire rolls on. (Smaller grooves allow the mud to pack in between the lugs and not be expelled.) The wide grooves also help the tire perform well on loose shale and rocks. (Grooves that are too close together can’t get a grip, sort of like a rock climber who can’t spread his fingers.)
The tire’s shoulder area has two designs to further enhance traction on loose or muddy surfaces. The varying shoulder width offers different biting edges for traction, which makes the tire the only choice when you are likely to encounter deep ruts. To take advantage of this feature, deliberately alternate right and left turns of the steering wheel; this will gently pinch the tire against the edges of deep ruts, which allows the shoulder lugs to claw at the sides of the rut and pull the vehicle forward. In effect, the tactic provides the feeling of an additional lower gear. Though it’s probably too aggressive for deep sand, this tire is best on loose surfaces, mud, and extremely deep snow.
* Unless you have the luxury of using multiple sets of tires for your 4×4, select a tire design that meets the worst driving conditions you expect to face. When you’re stuck axle deep in mud, you will forget all about how comfortable your highway rib tires have been.
* Make sure to buy replacement tires that meet or exceed the original equipment tire’s load capacity. Tires that aren’t designed to carry the load will wear out faster and make the truck handle poorly, especially when fully loaded.
* Radial tires dominate the market. There are many reasons for this, but one of the most important is that the design helps the tire envelop an obstruction rather than bounce off it or be punctured. Radial tires are available in each of the tire types presented in this guide.
* Light truck tires feature beefier construction. Generally, they can handle heavier loads and rougher terrain. Depending upon the design, they may ride rougher than passenger-car tires when you drive on the highway.
* Sidewalls are a tire’s Achilles’ heel. If you routinely venture into terrain with sharp rocks or thorny vegetation that can pierce the sidewall (such damage is not repairable), consider tires with actual three-ply sidewall construction.
* Be aware that the sophisticated electronic equipment found in modern trucks can be negatively affected by a change in tire size. There is an acceptable range, but if you exceed it your truck’s performance may suffer. Consult a knowledgeable tire dealer if you’re considering changing tire size.
* A set of good tires isn’t cheap. (The range of good tires runs from $400 to $800 depending on the brand, size, and whether you buy on sale.) However, buy the best tire you can afford. Cheap tires aren’t worth the money; they’ll wear out faster and perform poorly.
A Question of Size: When many truck owners think about new tires, they often look at new wheels as well. In this case, they often opt for wheels with wide rims, to give the truck a really macho look. Well, wide rims are fine if the truck spends most of its time on pavement, but if you want the truck to be a useful offroad tool, you should actually go with narrow-width rims.
Why? Because the narrower rim causes both beads of the tire to tuck in, which minimizes sidewall exposure. The net result is additional rim and sidewall protection from rocks and other objects that could cause air loss or tire failure. Moreover, the added sidewall flex allows the tire to absorb bumps, resulting in a softer ride.
Inflation Pressures: The number one reason for premature tire failure is improper inflation pressure. For best results, keep the tires at the inflation pressure recommended by the vehicle maker. (You’ll find this in the owner’s manual.) The inflation pressure branded on the sidewall is the maximum and should be followed only when the vehicle is carrying an extremely heavy load.
There are exceptions to this rule. A common offroad tactic is to reduce tire inflation pressure to improve driving performance. This is ordinarily done when driving over sand, where airing down widens and lengthens the tire’s “footprint.” Doing so puts more tire in contact with the sand, improving traction. Airing down also works on rock- or stump-studded trails. In this case, the lower inflation pressure allows the tire to wrap itself around a rock, which reduces the chance of a sidewall puncture.
When driving through this type of terrain, impact absorption takes precedence over quick-steering response. For this reason, tire inflation pressures as low as 25 pounds per square inch (psi) may be used–as long as speeds are less than 15 mph.
Be sure the tire has adequate load-carrying capacity at these lower pressures. To be safe, don’t go below 18 psi. The disadvantage to airing down is that you increase the probability of pushing a tire off the rim. Be alert.
Always make sure the tires are returned to the proper inflation pressures before you return to the highway. Severe internal tire damage or outright tire failure can occur when an underinflated tire is driven at typical highway speeds.
Driving Tips: Joe and I had parked the 4×4 at a small pullout next to the public access area and were uncasing our shotguns. The road in was ravaged; it was full of nasty ruts and gravel mounds, and the last 100 yards were especially treacherous because it dropped so steeply. As I slipped on my game vest, I heard the sound of another engine, and when I looked up I could see the driver was having trouble coming down the trail.
“Joe,” I yelled. “Get out of the way!”
Joe leaped behind our truck as the vehicle careened by and bounced off a huge tree. Fortunately, the driver wasn’t badly hurt–but his new truck had a nasty dent in the front quarter panel. He climbed out and said, “Sorry, boys. Didn’t mean to make you jump like that. I don’t understand it. I just put new offroad tires on this thing.”
New tires or not, if you don’t pay attention to the trail, trouble will always find you. Later, when I stopped by to talk with Steve White, Light Truck Tire Marketing Manager at
Uniroyal, and tell him the story, he said, “That guy made a classic mistake. He relied on technology rather than common sense to get him out of trouble.”
“Yeah,” I said, “I see that a lot.”
“What people forget,” White said, “is that good tires are only part of the package. You also need to hone your offroad driving skills. And you begin with equipment every driver already has.”
“And that would be?”
“Your eyes. You need to know what to do with your eyes. Too many people simply stare straight ahead, focusing only on what is immediately in front of the vehicle. Wrong! You should be using your eyes to gather much more information. For instance, what’s on each side of the truck? Are there sharp rocks or overhanging tree limbs? What about cactus? You need to know this. Now, take a look down the trail. What’s coming up? Deep ruts, a blind turn? Do you have an obstacle that you need to steer around? Or can you drive over it? You need to know this too, so trail challenges don’t come as a surprise.
“Always try to keep in mind what I call ‘the picture,’ which I define as where I want the truck to go, not where it currently is. That’s a big difference, but if you can do it, you’ll avoid a lot of trouble.
“In order to see ‘the picture,’ you need to be seated comfortably in the vehicle. You shouldn’t have to strain to reach the pedals or steering wheel, and you should be able to clearly see the gauges as well as the mirrors. Drivers who aren’t comfortable will get fatigued, and this affects your ability to control the vehicle.”
The next step, according to White, is to drive the vehicle with the correct speed and rhythm. When you get it right, you should be to hold a full cup of water without spilling it as you drive.
“You need to learn how to accelerate properly. Too many offroaders employ a herky-jerky on- and off-throttle type of driving. This only upsets the balance of the vehicle. Instead, gently accelerate to a level where you can keep relatively steady pressure on the accelerator. Make only subtle adjustments to slow down or speed up.
“Do all of your braking before you get to a turn, hole, or whatever it is that is forcing you to slow the vehicle. Remember, your brakes are going to be a lot more sensitive in dirt or sand because the tires have less traction. Make the braking action as subtle and as smooth as possible. If you do encounter a crisis, brake as hard as you can until the vehicle begins to skid. At that point, gently ease off the brakes in small increments to allow the tires to regain traction, but keep enough pressure on the pedal to continue to slow down the vehicle.
“Obviously, the slower you’re going when you get in a panic situation, the easier it will be to deal with. In fact, one of the major difficulties in trying to execute turns in offroad situations is excess speed. In many cases, the driver is not aware of vehicle speed–and most are going much faster than they think. And when that happens, you’ll find that the truck wants to keep going straight ahead rather than turning in the direction you are steering.
“That’s what I call a skid,” I said.
“Right. And it’s trouble, so slow down.”