Sunday, February 01, 2009
Sometimes in life you have to bite the bullet and not do things exactly how you want to do them, and this was one of those times. There was a new tire we needed to test, but some marketing geniuses told the respectable Nitto Tire company that they should be debuting these new tires with ridiculous wheel sizes before anything of acceptable rim size is released (in our eyes). Let us repeat a statement we've made in the past: We do not endorse wheel sizes being more than half the tire height. It just isn't right, off-road performance suffers, and it makes your truck ride like dookie. With that being said, we were embarking on a tire test of 285/50R20 (31-inch-tall) Nitto Dune Grapplers on 20x10 KMC Wheels Hot Wheels D-Backs.
By the time you read this Nitto will have Dune Grapplers in sizes you or us could live with on our 4x4s. As we were about to turn in this story, we received an e-mail confirming Nitto already has these sizes available: 285/75R16, 305/70R16, 315/75R16, 285/70R17, 315/70R17.
We can only imagine how well this tire would have worked on a 15-, 16-, or even 17-inch KMC wheel, as the Dune Grappler's performance on a 20-inch wheel surprised us in the sand dunes.
We got the snot beat out of us, and we learned a valuable lesson: Never bomb down dirt roads with no rubber in between your wheel and the dirt. We think we may have a dented wheel now, though it still seems to be holding air and riding fine. We couldn't air down the tire to smooth up the ride since there was so much wheel inside the tire, but aside from the ride, the Dune Grapplers seemed to get decent traction in dry dirt. If it got a little muddy, we fear that the tread voids would fill up pretty quickly.
We didn't get a chance to get too hard-core in our rockcrawling, considering we were in a stock Tahoe and couldn't deflate the tires, but we were able to get up on some steep slabs and roast the tires. The Dune Grapplers' soft rubber gripped the decomposed granite pretty well actually, and since the tread lugs aren't very tall, we didn't see any lug tearing or chunking.
The Dune Grapplers kicked butt on the highways and through canyon corners. Though the ride was harshened due to less sidewall, the soft rubber, wide contact patch, and smooth-rolling tread pattern kept these tires stuck to the ground. If your 4x4 is spending the majority of its time on the street or out in the sand dunes, we'd tell you to grab these tires as fast as you can.
We're not positive whether it was the increased pavement traction or addition of weight to each corner that kept us from doing burnouts, but the tires would now hook up and not squeal off the line like our old 31-inch tire package.
The tires did a little more spinning on wet streets than we expected and more than we'd want if the rain was pouring. And though we were unable to try the Dune Grapplers out in icy highway conditions, we fear that they would suffer for the same reasons that made them a little slippery on wet roads.
As for highway noise, they were quiet for an off-road tire, but not as quiet as we expected them to be. The noise level came in at around what a BFG All-Terrain or Cepek FCII would produce.
With a name like Dune Grappler, we knew that if there was one place these tires would really perform, it was in the sand dunes. We were (again) worried about the lack of sidewall in our tire-and-wheel package, as we've never really had much luck running in sand dunes with more than 15 pounds of pressure in the tires. But this time we had no choice because lowering the tire pressure did not bulge the 511/42 inches of sidewall and still let us sink in deep sand, and keeping the pressure low with 20-inch wheels would result in us pulling a tire off the wheel.
With all four tires filled with 20 pounds of pressure, we proceeded to bomb around in the sand. To our surprise we actually got some decent traction due to the lower-profile tread design that would not dig into the sand. In sand, you want to float on top with a large surface area. This tire's almost 12-inch-wide carcass held our 31-inch Dune Grapplers from sinking under our fullsize Tahoe, even without them deflated. We can only imagine how well these tires would work with a 35-inch diameter and a 15- or 16-inch wheel that would let an owner deflate to 10 or 12 pounds.
A while back we gave you a peak at Nitto's initial race Dune Grappler. After some serious R&D, Arciero/Miller and Nitto decided on this final race-tread pattern for the tire the Arciero/Miller race truck would run in the Baja 1000. They were the only truck running these tires this year, but we have a feeling you'll be seeing more guys running them during the next SCORE race. The Arciero/Miller team made it 950 miles of the Baja 1000 on competition Dune Grapplers, before an engine went dead and left them out of the race just a few miles from the finish line.
Our Dune Grappler test tire was a 285/50R20, which equals out to about a 31-inch-tall tire sitting around 12 inches wide. That left us 5 1/2 inches of rubber between the ground and the tire. We'd just have to be careful about potholes.
The Dune Grappler has a three-ply polyester construction utilizing side lug tread for increased puncture resistance. The tread, looking like little flames, cannot really be compared to other off-road tires. It seems to be a little less aggressive than an All-Terrain with a shorter lug height, but with a more intermediate void ratio than an All-Terrain. We checked the rubber hardness with an Intercomp tire durometer we ordered from Summit Racing and found these Dune Grapplers to have a reading of 60 (softer than most off-road tires). There is no siping on the tread lugs, and the tire features "sound absorbing blocks" that keep them quiet. Our initial opinions were that it would handle excellently on the roads and float well in the sand, but we weren't sure about how they'd work in the wet.
As for the mud: Well, we can probably all agree that this is no mud tire. The tread lugs are not deep enough to get a good bite in the goo, and with only a few inches of sidewall, there was really no way we could deflate these Dune Grapplers to try them in the mud.