What is a Mud Terrain Tire?

June 4, 2020
Story By
Ali Mansour

If there was ever something that was born out of absolute necessity it was the mud-terrain tire. Despite huge leaps in automotive technology over the past hundred years, the one thing that can stop even the most powerful and advanced vehicle on the planet quite literally in its tracks is mud. This is why the invention of the mud-terrain tire was so important and remains so today. But, what exactly is a mud-terrain tire?

The original mud-terrain tire wasn’t much more than a slightly refined tractor tire. With little emphasis on road comfort, the tires had substantial spacing between the lugs. The tread pattern mimicked what is still used on farm tractors across America today. The concept was simple—create a tire with large spacing between deep tread blocks so the tire could easily clear out debris with minimal tire speed.

These tires would primarily use a bias-ply construction. This is where multiple ply layers are set at opposing angles, which stretch from bead-bundle to bead-bundle. While originally thought to be stronger off-road, the bias tires were very heavy and lacked stability compared to a given radial. In fact, the early bias-ply versions of the mud-terrain tire did a rather good job of painting a extremely unflattering picture of for truck owners for many years. Still to this day when people think of a mud-terrain tire, they often associate it with loud, rough riding, and something not suited for a daily driver.

Thankfully, the evolution of the mud terrain has been a significant one. Instead of bias-ply, most modern mud terrains are of a radial construction. This helped significantly with on-road ride quality and stability. As tread design and rubber compounds have continued to improve, we are now in an era where using a mud-terrain tire for a daily driven vehicle is extremely common. To dive deeper into the modern mud-terrain radial, we’re taking a closer look at one of the most widely sold and used in the light truck market: the Nitto Trail Grappler.

Ejection!

A basic unit of measure with any mud-terrain tire is how quickly it can self-clean. Mud often requires momentum to pass through, but that’s not always an option on the trail. This is why tread spacing is so critical for a mud-terrain tire. These large voids allow debris to eject as the tire rotates. The slower the speed at which this can be accomplished, the more in control you’ll remain of the vehicle.

The Modern Contender

The modern-day mud-terrain radial is nothing short of an engineering masterpiece. To create a tire that is durable enough to dig through the roughest terrain and remain smooth rolling on the highway is something off-road enthusiasts could only dream about decades ago. While there are many contenders on the market, few hit the mark like the Nitto Trail Grappler. Given it’s offered in a variety of sizes and wheel diameters, it’s an ideal specimen for our mud-terrain breakdown.

Tread Spacing

If we had to narrow down the one feature that separates a mud-terrain tire from all others, it would be the amount of spacing placed between the tread. Just as you would see on a common farm tractor, these wide voids also provide increased grip in the dirt at lower speeds. These large voids are also why mud-terrain tires have more road noise over an all-terrain tire that would traditionally have less gap between the tread.

Kickout Bars

Just like a rowdy bar patron gets kicked out of the pub, mud-terrain tires have their own way to get rid of the unwanted riffraff. Theses raised features shown here between the main lugs of the tire are what’s known as kickout bars. These are engineered to help clear debris that might otherwise get stuck between the treads of the tire. After all, a tire packed with mud isn’t going to get you far down the trail.

Sidewall Tread

One thing we’ve seen more of in recent years in regard to the mud terrain is the addition of sidewall tread. While not exclusive to the mud terrain, it’s definitely a more common attribute. Though it may look like a simple styling cue, sidewall tread can become an important part of the traction equation off-road. From deep ruts to dugout hillclimbs, the more lugs you have fighting for grip, the better.

Leading Edges

For a mud terrain to be the most effective off-road, you’ll need well-defined leading edges. These allow the tire to cut through thick mud as well as give you the extra grip you need in more extreme off-road scenarios. This is why we see competitors in the highest forms of off-road racing turn to mud-terrains as their go-to tire.

Load Rating

Every tire has a specific load rating that indicates how much weight that given tire can support at a specific PSI. It’s worth noting that not all mud-terrains are intended for heavy-weight trucks, and you’ll nee to make sure that your mud terrain can handle the weight requirements of your vehicle and potential hauling needs. The Trail Grappler is one of the few mud-terrain radials that meets and exceeds the load requirements for ¾- and 1-ton diesel trucks, making it especially popular in the diesel segment.

More All-Terrain Than All-Terrain?

With the evolution of the modern mud-terrain tire, the discrepancies between that and an all-terrain tire have narrowed greatly. We often joke that given all-terrain tires do well in everything except mud, a modern mud-terrain radial is truly more “all” terrain tire. In fact, we’ve tested some all-terrains that are just as loud on the road as a mud-terrain, leaving us to wonder what’s the point of going with the tamer tread if it’s going to offer the same amount of roar?

Life Expectancy

The one area that a mud-terrain tire can fall a little short is in life expectancy. As a general rule, you typically will not get as many miles out of one as you would an all-terrain tire. While we have personally witnessed Trail Grapplers with more than 50,000 miles under their belt, we wouldn’t bank on any mud-terrain outlasting an all-terrain tire.

Mud Grapplers

We can’t talk about mud tires without at least mentioning the grandfather of the Nitto Grappler line, the Mud Grappler. While mud is in its name, Nitto classifies this tire as an Extreme Terrain tire. The Mud Grappler pre-dates the Trail Grappler by sometime, and while it has plenty of confidence in every off-road terrain, it’s generally more reserved for dedicated off-road enthusiast that are willing to tolerate a bit more road noise in exchange for a no-holds-barred off-road tire.

Hybrid Terrain

We would be remiss if we didn’t at least mention the fastest growing light truck tire segment- the hybrid terrain. Like the category alludes, this line is meant to fill the void that rests between a traditional mud terrain and all-terrain tire. At the forefront of this tire revolution is the Nitto Ridge Grappler. It has all but reinvented the way we look at what a tire can be. While not as aggressive as the Trail Grappler, but far more menacing than the Terra Grappler G2, the Ridge Grappler mergers the needs and wants of people on all wheeling fronts. By offering large tread blocks with deeper and larger voids more typically found on a mud-terrain tire, the Ridge Grappler conquers muddy and rocky terrain in a way no all-terrain can touch. However, using a unique tread pattern and sipes throughout the tire, means it has the on-road comfort, performance, and longevity that is far more important to those needing to get the most out of their tire.