Interco Super Swamper SSR 33x14.50R-15LT

Interco Tire Corporation knows the importance of good traction, reflected by their slogan "Tough Tires for Tough Terrain." They have specialized in maximum-performance off-road light truck tires since 1972. Their product lineup illustrates their expertise. The Super Swamper series of tires has diversified over the years to meet the various needs of off-roaders, yet they all share a few unique features that make Super Swampers widely considered the benchmark for off-road tires.

Putting their tires at the top of their class is Interco's distinctive patented Three Stage Lug tread design. Originally designed for mud, alternating widths of tall shoulder lugs allow the tires to bite into soft surfaces and still self-clean ? even at slow rotational speeds. Extreme rock crawlers have found that this unique tread pattern can also grab the edges of rocks and pull their vehicles over obstacles that many other tires simply cannot grip.

Other Super Swamper features are also designed to maximize performance. Deep tread blocks and thick sidewalls provide maximum protection against punctures and tears. Some Interco's tires even have sidewall tread blocks that are constructed of the same extremely soft rubber compound as the rest of the tire's tread to provide more traction than competing tires.

However, making off-road performance the highest design priority of the Super Swamper made on-road drivability come in a distant second. Accelerated tire wear, a rough ride, high levels of noise and diminished handling capabilities are the on-road tradeoffs made with such aggressive off-road tires. In the past, desire for maximum off-road performance meant either making the sacrifices on-road or using two different sets of tires: an all-terrain tire on the street and the Swampers on the trail. This is a cumbersome and expensive solution that Interco worked hard to address.

I believe that with Interco's release of the Super Swamper SSR, the on-road tradeoffs of the Super Swamper design are truly a thing of the past.

Design

Can a Super Swamper really be street-friendly? I was expecting the SSRs to be much improved on the street when compared to the Swamper TSLs, but within the first mile I knew there was something special about these tires. To put it bluntly, I can't believe how nicely these tires perform on the pavement. A closer look at the design reveals why the SSR's street performance is so much better than I've experienced with other mud-terrain tires.

First ? and perhaps most importantly ? the Swamper SSR is a radial design. Radial tires generally perform better than bias ply tires on the street; riding more smoothly, providing better directional stability, greater resistance to tread punctures, running cooler and having a more even contact patch. They also have longer tread life and their carcass is resistant to forming "flat spots" when the vehicle is parked.

Secondly, Interco paid careful attention to the tread pattern. The SSR is the next generation of Interco's patented Super Swamper TSL tread pattern, which itself is the result of nine years of development. Alternating large, medium and small shoulder lugs flank two rows of large, interlocking sideways chevrons, providing maximum omnidirectional traction. The most immediately recognizable change from the earlier Swamper designs is a slightly tighter tread pattern. The voids between the center tread blocks are particularly narrow and have a bend in them, both features greatly cut down on tire noise and place slightly more rubber on the ground. Another nice detail showing the quality of this tire's construction is the equal sizing and spacing of the tread lugs around the entire circumference of the tire. Many competing tires have a tread design that is compacted or elongated in sections in order to adapt a larger or smaller sized tread mold to the carcass. By contrast, this tire was designed from the outset to be a 33x14.50, not a "stretched" 31x10.50.

Interco's designers didn't stop there. The rubber compound used in the tread lugs is extremely soft. Multi-directional sipes within the center tread blocks allow for increased flex of the individual tread lugs, which in turn increases traction and tread life while reducing heat buildup. The sipes also provide additional channels through which rainwater can travel and more biting edges for traction in snow and ice.

Finally, sidewall treads of alternating height provide additional traction in deep, soft surfaces and can aid in traction in ruts and on rock. They also protect the sidewalls from scuffing and gouging in the most severe terrain, which could damage the tire.

Interco's Super Swamper SSRs are available in a broad selection of both standard and non-standard sizes. I chose their 33x14.50R-15 for the additional grip and floatation the wider section width provides. While most manufacturer's tires measure up to be shorter than their rated size, the lineup of SSRs runs big. My previous set of 33x12.50 radial mud-terrain tires measured a common 32.6 inches tall with a 9.1-inch wide tread. These SSRs are a full 33.7 inches tall with 12.4 inches of tread. They should really be rated as a 34-inch tire, and with their additional width they require just as much fender well clearance as other 35x12.50s when mounted on a truck with highly flexible suspension.

On-Road Performance

Simply put, these tires do not drive like a Super Swamper. I was expecting a decrease in street performance when swapping from a standard 33x12.50 radial mud-terrain to the big, heavy 33x14.50 SSR, but I couldn't have guessed more incorrectly. These tires literally drive like an all-terrain type tire on the street!

Even at full highway pressure, the ride is smooth. Freeway expansion joints, driveway curbs and even lane reflectors are nearly undetectable. At slower speeds, the characteristic vibration from large, widely spaced tread blocks is nonexistent.

Pavement traction is very impressive. On certain 90-degree turns from stop signs along my regularly driven routes, the locker in Project Buster's rear differential would easily cause the old tires to chirp and squeal, especially with liberal use of the throttle. The Swampers, however, absolutely refuse to let loose. Even when dropping the clutch mid-turn, the inside rear tire does not give up enough traction to let out a little chirp.

Cornering grip has also increased substantially. One particular road I frequently drive is a steep uphill, windy one-lane paved road. Its sharp, blind turns, narrow width and bumpy surface limit normal speeds to 10 miles per hour. With every previous set of tires, the large, mid-turn bumps, when taken at high speed, would create enough front axle hop to cause the front tires to lose grip and plow ahead several feet until grip was restored by the settling of the suspension. The SSRs surprised me by not losing grip at all, even at a much higher speed. The truck's body still bounces on its suspension in the same manner, but the front tires don't plow ahead as other tires on my truck have always done.

Similarly, braking performance has also improved. Although the 4-wheel disc brakes on Project Buster have enough power to lock up all 4 tires, breakaway and modulation are smooth and easily controllable. There are no surprises.

Rain performance is better than I expected from such a wide tire. The large, deep voids, siped center tread blocks and wide center channel help direct water out from under the tread lugs and keep the rubber in contact with the pavement. In Northern California's heavy downpours I could not get the tires to hydroplane. Only in deep pools of standing water did I notice the tires' additional width, at which time the truck would pull towards the side on which the puddle was located. A heavier vehicle with a longer wheelbase would undoubtedly resist this tendency much better. With a high lift and no mud flaps on my truck, I found that nobody tailgates me without being drowned in a solid wall of water.

The most easily recognizable differences from upgrading to this set of Swampers are caused by the additional rotational mass. In addition to being physically larger than the previous set of 33x12.50s ? 1.1 inches taller and 3.2 inches wider ? the sidewalls and tread areas of the tire are significantly thicker and thus heavier. Each 33x14.50R-15 Super Swamper SSR weighs in at a hefty 77 pounds! A set of 4 mounted on steel 15x10 wheels is over 400 pounds of mass that requires a lot of energy expenditure to get rolling and hauled back down to a stop. A firmer push on the brake pedal is needed for the same rate of deceleration and acceleration has taken a noticeable hit.

The most impressive characteristic of these tires' on-road performance is their reduced road noise. Compared to other popular tires, these tires are nearly silent! I compared them head-to-head against vehicles equipped with Baja Claws, BFG Mud-Terrains, Wild Trac Radial RVTs and Interco's own Super Swamper SXs and Boggers. I found the Swamper SSR to be much quieter than other tires, even those having much less aggressive tread patterns. On the street, the SSR's noise-level seems to be on par with many all-terrain tread patterns. I did not have a decibel meter to scientifically test the tire's sound levels, but sticking my head out the windows at highway speed revealed that the tires make more wind noise than road noise.

I did find that the SSRs get progressively louder as the inflation pressure drops, however. Running on pavement with less than 8 pounds of pressure, they sound like Swampers are "supposed" to and at less than 4 pounds, they positively howl. They also sap a lot of horsepower with their giant footprints as they scrub away the rubber, so proper inflation pressure is important to tread life.

I am very pleased with their on-road performance, but enough with the on-road stuff! This is Off-Road.com after all.

Off-Road Performance

If ever there was a ?perfect tire for every type of terrain,' in my opinion the Super Swamper SSR comes closest to being just that. There has not been a single instance off-road where I was not very impressed with the performance of these tires compared to others I have run on Project Buster. I wasn't surprised by their traction though, because even with the SSR's friendly road manners they are still Super Swampers.

Radial tires are known for being less forgiving of trail abuse than bias ply tires. Radial designs have a sturdy, puncture-resistant tread area and a flexible carcass that can wrap around the terrain and increase traction. However, bias ply tires have a thicker sidewall that is more resistant to punctures and are more tolerant of twisting and bending forces than a radial tire's sidewall. Bias ply tires can also have the tread extend onto the sidewall, a more common trend among newer tire designs because of the increased grip in ruts and rocks.

Interco has done a great job of addressing the weak points of the radial design with the design of the new SSR. Although only of 2-ply construction, the sidewalls are extremely thick and puncture-resistant. Interco claims that the sidewall is up to 3/8-inch thicker than other mud-terrain radials and I don't doubt it. Compared to the previous set of tires on my truck, the sidewalls on the SSRs appear to be easily twice as thick. Additionally, the tires have tread lugs cast into the sidewalls. Admittedly, they are not as aggressive as the sidewall tread on the bias ply Swamper SX and the competing Baja Claws, but I put them to good use in varied off-road terrain and they proved their worth to me.

I was initially concerned that sidewall thickness would cause the carcass to be too stiff to flex well under a truck as light as a Samurai. At the beginning of my testing I did notice the stiffness of the sidewalls. After some high-speed off-road driving at reduced inflation pressure to build up some heat and some good flexing in the rocks, the sidewalls loosened up quite a bit. As the pictures indicate, SSRs conform very well to rocky terrain despite their thicker sidewalls.

Interco makes the 33-inch SSR in the standard 12.50-inch section width, but I equipped Buster with the 33x14.50's. Although tough to fit within the fender wells, the wider tread really makes a big difference in off-road traction. Not only is floatation increased ? already a Samurai strong point ? but there is also a stickier rubber compound and more biting edges that claw at the terrain. When it comes to the wide versus narrow tires debate, the same theory that applies to bulldozers and snowmobiles applies to a 4x4.

Snow

Immediately after mounting and balancing the tires, I headed to South Lake Tahoe's Echo Summit. At an elevation of 7300 feet, four feet of snow was below average for the time of year, but it was perfect for testing the tire's capabilities. On plowed roads with a mixed surface of snow and ice, traction was unbelievable compared to any previous set of tires we have used. Even at highway inflation pressure in 2wd, breaking the rear tires loose required deliberately dropping the clutch; merely holding the throttle to the floor wasn't enough to spin the tires. Later in the product review testing, I went tearing up through the ice and snow to Crestline in Southern California's San Bernardino mountains at breakneck speeds and found that even on 10 mph hairpin turns with my foot to the floor, I could not get the front or rear tires to slide. The siped center lugs and extremely soft rubber compound grip snow and ice almost like they're on pavement.

At street pressure, the tread packs up quickly in deep snow due to a lack of carcass flex unless high rpm's are used to clear the tread. However, once aired down to proper snow pressure (1-2 psi works well for lightweight Samurais) I was basically unstoppable. On icy plowed roads, the tires refuse to break traction. In deep powder, they provide a huge amount of floatation so the undercarriage doesn't drag through the snow. Additionally, as the tire rotates the tread flexes and immediately drops all the snow from the voids between the tread blocks, even at crawling speeds. The additional width of the tires and wheels makes them much more laterally stable around turns at such low inflation pressures than narrower tires of the same sidewall height.

A particularly nice feature of the Swamper SSR in snow is the lateral grip, thanks in large part to the extremely wide groove that runs down the center of the tread. Climbing diagonally up the side of a hill in snow usually results in a downhill sideways slide of the vehicle; not so with these tires. The same holds true for reversing through deep ruts. Without 4-wheel-steering, it is usually very difficult to make a turn in deep snow while backing up because the front tires want to follow the ruts the rear tires make. The design of the SSRs makes such maneuvers comparatively easy. Directional tires such as Boggers and Baja Claws are put at a big disadvantage in such circumstances. The amount of lateral traction these tires can find in slippery surfaces is amazing.

We left tracks on all the unplowed roads on the summit. No matter how steep the hills or how deep the snow drifts, I simply could not get our truck stuck. I pulled out numerous stuck vehicles and plowed through snow as deep as the hood, going places that no other tire has been able to take us in our years of snow driving on the summit. The Super Swamper SSR is the best snow tire I have ever found. Their only weakness is that they aren't pinned for mounting ice studs.

Rocks

After playing in the snow, I drove the truck to Phoenix for an entirely different type of terrain: the famous Arizona rocks. In contrast to the smooth, rounded rocks of California's Rubicon Trail, Arizona's rocks are sharp and jagged, known for being extremely rough on tires. It is for this reason that most of the extreme rock crawlers in the area choose bias-ply Swamper SXs, but I wanted to see how well a radial tire from Interco could fare.

On such a lightweight vehicle, 1-2 pounds of air pressure works well in snow, but on the rough terrain and solid traction of rocky trails I found 6-7psi is needed. Heavier vehicles would require more air pressure, but the SSR is designed to flex well even at higher inflation levels. One drawback to such a large tire is the amount of time it takes to inflate and deflate them, so a high-volume compressor is recommended.

I immediately noticed how well the SSRs grip rocks. Aired down, the carcass flexes enough to allow the tread to wrap around individual rocks. Where other tires with harder rubber compounds spend a lot of time slipping on dusty or sandy rocks, the SSRs stick like glue due to the soft, squishy rubber. The sipes within the center tread blocks open up to give more edges to bite into the surface and find traction, evidenced by the grains of sand and small pebbles that get trapped within the sipes. The Three Stage Lugs grab hold of the edges of rocks to pull the truck straight up and over large obstacles that would otherwise be nearly impossible to climb. Even the sidewall treads proved to be very useful, not only by gripping the rocks but also by taking the brunt of the trail scuffing, protecting the sidewalls from damage.

The width and weight of the tire and wheel combination also allows for an increase in off-camber stability. At a full 14 inches wider than the stock Samurai's width, rollover worries only begin to occur in the most extreme situations.

The only negative point I found with these tires in the rocks is that the tread blocks do get chewed up a bit, due to their extremely soft rubber compound. This is an unavoidable trade-off that really does not affect the tire's performance off-road or on; it is really only a cosmetic issue that can be minimized by avoiding unnecessary wheel-spin.

Dirt Roads

Just about any tire can successfully navigate a dirt road, but there are some important factors that need to be considered. Unpaved roads can contain any number of unexpected obstacles that can shred a tire, especially if the vehicle is driven at high speeds. A durable tire is a must, especially when crossing Arizona's deserts with the throttle wide open. Sharp rocks, unseen wash-outs and cactus can quickly expose a tire's vulnerabilities. Additionally, a good tire must deliver a smooth ride and predictable cornering, even in a full opposite-lock slide.

A tire with stiff sidewalls will inherently deliver a rougher ride and again Interco proves that thick sidewalls don't necessarily have to be stiff. At highway inflation, high-speed dirt road travel remains comfortable. However, by releasing excess pressure for rough trails the ride quality can be improved without excessively degrading handling. Bombing through deep washes, four-wheel drifting around corners and full-throttle blasts across piles of loose, sharp rocks proved the tire's durability. Traction again impressed me, especially lateral grip. On loose, unpaved surfaces even my deliberate attempts to slide the rear end out failed. Under most circumstances, light understeer prevails with neutral 4-wheel drifts resulting from blatantly excessive speed.

The tires survived their punishment in Arizona with aplomb. I suffered no punctures, tears or leaks; the only evidence of their thrashing being a few grooves in the tread from the rocks and a bunch of cactus spines stuck into the carcasses.

Sand

Project Buster spends a great deal of time off-road at the Samoa Dunes County OHV Park on California's far North Coast, so a tire's performance in sand is important to me. Much of the same theory for driving in snow applies to sand, with floatation being the biggest factor. Again the Super Swamper SSR impresses, providing more traction at highway pressure than the truck's previous 33x12.50s could find when aired down.

The large footprint beneath the four tires distributes the vehicle's weight across the top of the sand, preventing the truck from sinking. Climbing sand dunes requires putting a lot of horsepower to ground without digging down into the sand, so these big tires are perfect. They throw huge rooster tails as long as the throttle pedal stays planted to the floor. Even when momentum stops and these tires begin to dig, they oftentimes dig forward instead of down, continuing their forward progress. With their aggressive tread pattern, though, once they start digging it's time to throw in the clutch and back down the hill because they'll dig until the truck's frame is hopelessly sitting in the sand with the tires hanging within 4 giant holes.

Mud

Mud is the Super Swamper's forte and the SSR doesn't disappoint. Although in certain conditions a narrow tire can dig down through the surface mud to the hard subsurface to find traction, a wide tire with a big knobby tread pattern can find more traction in the deep stuff. It is here that the Super Swamper's patented Three Stage Lug design is in its element, clawing through mud and self-cleaning better than any other light truck tire I have experienced.

Swimming through mud holes and clawing their way up steep, muddy logging roads in California and Oregon's coastal mountains gives the SSRs a chance to really have some fun. Protruding several inches beyond even the fender flare extensions, the TSLs fling clods of mud into the next county as they find traction where other tires fail.

As good as these SSRs are, there are tires that will perform even better in mud. Interco's other Super Swampers have even larger tread blocks and voids and the Super Swamper Bogger is the ultimate mud tire. However, their more focused design detracts in other terrain where the SSR shines.

Conclusion

I tried to hard find a weakness in these tires; in fact, I pushed Project Buster so hard during testing that I grenaded two U-joints. In 3,000 miles of hard driving, from city and highway to rock and mud to sand and snow, I tried to cover all the bases, yet many of the little rubber casting nubs still haven't worn off the tread blocks!

I expected Interco's Super Swamper SSR to be a great tire, but I was surprised at how consistently well they performed in every test I could think up to put them through. Dedicated street tires will perform better on pavement and dedicated mud tires will perform better in mud, but no other tire I know of today can beat the performance of the SSR in such a wide variety of terrain. And as for looks, only a set of Boggers can generate more stares from passers-by.

Although the SSR provides extreme off-road performance, it was also clearly designed for use on pavement. This intent is reflected by the broad selection of sizes designed to fit both stock and highly modified trucks. Sizes range from 27 to 37 inches in height, 9.50 to 14.50 inches in width and for wheels from 14 to 17 inches in diameter. This is truly a tire that performs equally as well on trucks that never leave the pavement as it does on trucks that are used strictly off-road.

The biggest downside to these tires is they are among the most expensive off-road tires on the market. However, this is one case where the old saying "you get what you pay for" holds true. Evidenced by their lack of tread wear in spite of the abuse they have taken during my tests, I anticipate that these tires will not need replacing for a very long time. And when it does come time for a new set of tires, I will definitely be looking for another set of Super Swamper SSRs.

--Geoff Beasley