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Testing the New BFGoodrich Mud-Terrain T/A KM3

Posted in How To: Wheels Tires on February 25, 2019
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Ask anybody how tough, loud, or capable their tire is and chances are the answer will end with the phrase, “compared to a BFG.” It’s kinda funny, but it’s also kinda true. Since the late 1970s, BFGoodrich tires have become the standard by which the rest of the off-road industry is measured. That’s why changes to such a tried-and-true design aren’t something the company undertakes lightly and half-assedly.

BFGoodrich busted into the mud-terrain market in 1980 with the original BFG Mud-Terrain T/A. Other than undergoing tweaks in 1988 and 2001, the tire remained fairly familiar until it was completely revamped in 2007 as the Mud-Terrain T/A KM2. The KM2 did away with the classic angled zig-zag tread blocks for smaller, blockier lugs that resembled something of a baby Krawler T/A KX. Now BFG is upping the bar with the Mud-Terrain T/A KM3, infusing more race-proven technology into its everyday mud offering.

For starters, the KM3 boasts a whole raft of improved percentages compared to the KM2 it’s replacing. The Mud-Phobic bars, as the protuberances on the tire’s shoulder are called, help diminish suction and allow the tire to release mud and soft soil from the tread, giving a 5 percent bump in mud traction. The Krawl-TEK compound, coupled with a tread and carcass design (BFG calls it Linear Flex Zone) that lets the tire envelop obstacles while climbing, results in an 8 percent improvement in rock traction. The KM3’s CoreGuard Max sidewall technology (borrowed from the Baja and Krawler lines) ups sidewall strength a whopping 27 percent. Finally, a chip and tear resistant compound keeps the blocky treads from shedding rubber all over the trail. In short, improvements all around with only a slight increase in tire weight as a tradeoff.

To test these claims for ourselves, we pulled our 1989 Wrangler (Project Why-J) out of the barn and shod the 15x8 Ultra Series 50/51 wheels we got from Summit Racing Equipment with a set of 32x11.50R15 Mud-Terrain T/A KM3s. We really appreciate the fact that BFG still supports 15-inch wheels for vintage 4x4s—that’s a plus in our book right there.

The BFGoodrich Mud-Terrain T/A KM3 employs every trick in the mud performance book, especially these ribs between the outer tread blocks and the circumferential bars that run between the sidewall treads, which BFG calls Mud-Phobic bars. These help break suction created by thick mud and wet soil, allowing the tire to clean itself as it rotates and get a fresh bite into the terrain.

The first thing we noted after pulling away from the tire shop is a moderate tread hum. It’s nothing close to the full roar of a dedicated bias-ply mud tire, but you can audibly tell you’re not driving on a mild all-terrain or “tweener” rough-terrain tire. On-road grip, predictability, wet weather handling, and even tread wear receive top marks. There’s no adverse quirks to report other than we have been running our street pressure at the same 28 psi as our old 31x10.50R15s and noticed that after almost 2,000 miles the outer tread lugs still have traces of the casting nubs, so we’ll need to drop our pressure to get the full tire into contact with the street and prevent the center tread from wearing prematurely.

Off-road the first thing we did was take advantage of rare SoCal rain to put the M-T KM3 tires through some light mud and soft, tacky soil. They chewed through with ease, and what little soil the tires picked up was quickly evacuated. Rocks? No chunking, punctures, sidewall damage, or other nastiness to report.

We really dig the tread that envelops the sidewall, and have found that at lower single-digit pressures it acts more like an extension of the tread, especially when turning. The center tread blocks are angled just about every way imaginable to provide gripping traction not only going forward, but also laterally and diagonally. In short, the treads gripped and grabbed no matter what, providing a sense of stability and security at whatever angle the Jeep was poised. And true to form, the wide-siped center tread blocks and flexible carcass just wrapped up rocks and trail incongruities.

No matter where we put the Jeep, these new BFGs excelled and then some. You can be sure we’ll be eyeballing some KM3s in a larger size for our hardcore trail vehicles.

The center tread blocks are generously siped—to the point where we’re not even comfortable calling them sipes. They’re more like voids. The voids between them allow the blocks to open up and shed material that’s been picked up as well as to better conform to the terrain. As the tire flexes the voids open up, allowing most picked-up material to be evacuated. But even if there’s material inside the tread voids, the outer tread blocks still have plenty of gripping edges to bite and chew and help claw the vehicle forward.
Despite the manual steering, the test vehicle is equipped with front and rear lockers and we do actually drive it in rocks. During some wet-weather rock work after we first mounted the tires, we wound up putting the sidewalls into potentially damaging situations more than we intended. Our Ultra 50/51 wheels got a bit chewed, but the combination of BFG’s Krawl-TEK compound and CoreGuard Max sidewall technology allowed the KM3 tires to escape virtually scratch-free. At the time these photos were taken, our tires had about 2,000 miles on them and still look virtually brand new.

Tire Specifications

BFGoodrich Mud-Terrain KM3
Size Tested: 32x11.50R15
Type: All-terrain M+S
Load Range: C
Maximum Load (lb): 2,535 @ 50 psi
Sidewall Construction: 3-ply polyester
Approved Rim Width (in): 8-10
Tread Depth (in): 18/32
Tread Width (in): 9.5
Section Width (in): 11.4
Overall Diam. (in): 31.5
Weight (lb): 55.2
Sizes Available: Several sizes available, from the 29-inch 235/75R15 up to 39 inches for wheel diameters of 15, 16, 17, 18, and 20 inches.

Sources

Summit Racing
800-230-3030
www.summitracing.com
BFGoodrich
877-788-8899
www.bfgoodrichtires.com

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