Interco SS-M16 Off-Road Tire - 4-Wheel & Off-Road Magazine

David Freiburger Contributor

Novelty tires are everywhere these days. We've got treads with doggies on them, some with flames, and others with people's initials being used for traction. The latest entry is almost the least conspicuous: The SS-M16, part of the Super Swamper family from Interco Tire Corporation. The SS-M16s have silhouettes of rifle shells between the side lugs, plus ribbed icons reminiscent of sergeant's insignia punctuated by remarkably detailed depictions of the firing-cap end of an M16 round. You'll have to lean down to get most of that; two steps back and it's the super-aggressive sidewalls and junior-Bogger-ish tread pattern that lend curb appeal.

131 1009 Interco Ss M16s driver Side Front View Photo 34153563 At 75 psi on 16x61/2 wheels (an inch narrower than recommended), and with roughly 800 pounds in the truck bed, the 295/75R16s were 331/8 inches tall with a static loaded radius of 163/16 inches, and had a section width of 117/8 inches. These are the nearly ideal, maxed-out size for this 3/4-ton Ram with stock suspension, as we experienced only a little love rub on the rear panel of the front wheelwells. On the street, they don't rub at all.

Not that we publicly admit to buying tires for cosmetic reasons, but-OK, yeah, we wanted cool-looking rubber for our tow rig/daily driver that's also used for desert exploring. We tried the M-16s because we've rarely met a Super Swamper we didn't like. To name names, it's the Thornbird and Trxus STS meats that were dropped from our Christmas list, but the M-16s land between those two on the scale of aggressiveness and end up more effective overall.

Our test rig was a '99 Dodge Ram 2500HD with a V-10, and the tire size was 295/75R16. Because of our towing needs, we were attracted by the E load rating, with each tire capable of carrying 3,970 pounds at 80 psi in a non-dualie application. The SS-M16s are available in sizes from 31x10.50R15 to 40x14.50R24 and for wheels with diameters of 15, 16, 17, 18, 20, 22, and 24 inches

We've put about 3,500 miles on the tires so far, all of them impressing us with relative quietness. At 75 psi the M16s roll almost silently up to 40 mph and hum at acceptable levels up to 85 mph, which is when we chickened out. There's zero low-speed thump or high-speed steering-wheel shake. The high pressure of the E-rated tires meant a firm, typical 3/4-ton truck ride, but the tires were well rounded and they easily balanced without an absurd number of weights. We were very pleased with the stability while trailering, even having stepped up a size from our old tires to these ones. We were able to take a few trips in the rain, where the M16s were not scary but also not a first choice.

131 1009 Interco Ss M16s sidewall Lugs View Photo 34153473 The chunky sidewall lugs are decorative, but not lacking in function.

Off-road, we couldn't shake the impression that the trick sidewalls and chunky outer lugs work better than the center tread. For example, on speedy dirt roads, the M16s turn in well but don't hold the cornering slip angle in a way that makes you think they really mean it. In rocks, you can count on the outer edges to take you places, but not so much when the center tread meets an obstacle head-on. We found ourselves hunting crevices for side-lug grippage; see the captions for information on the tread's survival in rocks.

We were happy with the performance in hillclimbs with moderately loose rocks, and the propulsion through coarse alluvium was better than with any other tires we've had on the Dodge. Our truck's brutal wheelhop ended any testing in fine sand. SoCal weather eliminated snow and mud trips, though intuition tells us that, other than highway use, those are the preferred elements for the M16s.

Interco offers better mud tires in the traditional Swamper and Bogger if you can handle the noise, a capable conventional mud-terrain in the Trxus MT, and the most pavement-happy option in the all-terrain VorTrac. But if you need that in-between level of daily driver tire that's better than an all-terrain, more aggressive than an everyday mud tire, and friendlier than extreme tread designs-and you also need to look badass-the M-16 is for you.

PhotosView Slideshow At max pressure, the contact patch is only as wide as the edges of the inner tread blocks, which really helps to quiet down the on-road howl. We progressively aired down to discover the point at which the entire width of the tire contacted the pavement, and that was 40 psi. Our gas mileage dropped by almost 1 mpg when highway driving at the reduced inflation, and steering input was notably gushy. Here's what we found most interesting: This is at 40 psi, which we consider very high for this amount of flex. More importantly, look at the extreme fold in the lug. Granted, it's a medium-heavy truck that's heavier than most dedicated trail rigs, and the flexion helped performance in the rocks, but this is more tread deflection than we'd expect. It's as if the 10-ply carcass is rigid and most of the wrap is in the lugs. Finally, here's the reason you won't want to run SS-M16s on a rock rig. Look carefully at the tread face and you'll see that many of the blocks are split outward from the deep sipes, and some have chunks missing or are torn off altogether. This is the result of one day in the rocks. The rear tires were worn significantly more than the fronts, indicating that this problem is exacerbated by wheelspin and/or load, and perhaps by a too-low inflation for the tire's construction. Whatever the case, these M16s and rocks are not buddies.