It's been three years since we initially tested the Nitto Mud Grappler's ("Neat-O Nittos" May '04), and with many more miles and experiences on them we felt it might be time for further review. But more than that, we have an exclusive first-time test of a special competition-only sticky rubber compound set of MGs and wanted to show you what the deal is with them as well.
In the few years that we've been learning about Nitto we've found that the company is constantly striving to make its tires exactly what off-road enthusiasts want in both appearance and performance. We've had in-depth talks with the engineers and media folks and even sent representatives to Nitto's headquarters in Japan (last month) to see how these rubber doughnuts are made, and we have been constantly rewarded with Nitto's true enthusiasm for the recreational four-wheeler.
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First, the off-the-shelf tires. Back in 2004 we were a bit wary of the fact that Nitto was only offering tires for 18-plus-inch rims, but its line has since expanded to offer Mud Grapplers for 15-, 16-, 17-, 18-, and 20-inch rims in diameters up to 37 inches. We mounted a set of LT37x13.50R17s onto some American Racing Mojave rims and slid them under our daily driver/weekend wheeler for a few thousand miles of testing. | 
The Mud Grapplers definitely have a more aggressive sidewall than the previous tires we were running and the A.R. cast-aluminum rims gave our truck just the look we were striving for. Plus the wider footprint and 2-inch-taller rubber should help both ground clearance and flotation. |
So how has our experience been with these tires? Well, let's get one thing out first: These tires are loud on the highway. They have a whine like a double-prop airplane, though only at high speeds, and after a while you get used to it, but you'll definitely notice it when you first bolt them on. Under about 40 mph the noise drops off and you barely notice the deep lugs slapping asphalt at surface-street speeds, but then again if you're looking for a tire like this, quiet is most likely a low priority. Off road we were very happy with the tires performance. We spent a long weekend exploring back hills, and even with a 3 1/2-ton test truck, we always felt like we had solid footing whether climbing or descending off-camber knolls. It seems to us that the deep tread depth, sipped lugs, and the claw with reptile skin design all work as well as they look.
Here is something few magazines ever get to do: Take a set of tires never before seen, designed exclusively for competition and costing tons in research and development time, and go beat the bajeezus out of them. In fact, even though many tire companies have developed special compound competition tires, we've only tested one set before and those were the BFGoodrich Krawler T/As we ran on our Ultimate Avalanche back in 2003. The idea behind these competition-only Nitto Mud Grapplers was to mold them out of a super-soft and sticky compound that will better grip the rock for those challengers in the many rockcrawling competitions. How soft are these? Somewhere between marshmallows and pencil erasers.
Again we bolted the Mud Grapplers to some American Racing wheels, but these were modified with OMF bead locks to keep these stickies from slipping a bead in the rough stuff. We then headed to the desert for some rock abuse. We quickly found that the tires can take a ton of abuse without puncture. We battered these tires mercilessly, stuffing them between sharp boulders, spinning them in tight notches, and forcing them to drag our rockcrawling Toyota over crazy-guy lines we knew were nearly impossible, just to see what they could handle. What's really odd is that the rubber seemed to turn a pale shade of blue after we used them for a weekend in the rocks...probably due to the special recipe of rubber they are made of.
The pliable competition compound grips rock formations that street-legal tires would be clawing at in vain. But this same sticky tread also picks up dirt and sand more easily, and as such, needs to be spun on the rocks a bit for cleaning and warming up the lugs. Once you get the tires warm they get even stickier, helping to pull the truck up over obstacles. However, the soft compound also scrubs off quickly with the mistreatment of testing and we often left small piles of warm sticky rubber on some obstacles as we proceeded up the trail.
So what do we think of these motorsport-only tires? They grip excellently in the rocks, making some obstacles that we've struggled with before a non-issue, and holding many steep or off-camber lines that a harder rubber would slide off. However that same beneficial soft-rubber recipe also results in a short-lived tire that would definitely not be recommended for street use. One trick we've learned from some pro rockcrawlers is that before you run competition compound tires it is beneficial to wear them down a bit. This helps remove any slippery release agent that may have come on the tires and results in a broader front edge of each lug, giving it more bite. As such we'll keep testing these Nittos to see how they progress. Many of you know that the BFGoodrich Krawler tires have ruled the roost in the rockcrawling scene, so how do these Nittos compare to BFGs? With such a long time since we tested the comp-only red-label BFGs we wouldn't feel right making a claim that either are better, but the Nittos are definitely an aggressive design that we feel will allow drivers running them to be competitive, and should certainly be considered if you are building a buggy and planning to compete. If or when they will be offered to competitors or the public is still unknown, but the Japanese team of Masa and Naozumi Tsuda will be running the 2007 UROC Pro Modified series in a Nitto-sponsored vehicle, and in their first U.S. competition (SuperCrawl 2006) they took sixth place while running competition Mud Grapplers. Not too shabby.