We Test 'Em In The Snow
Which are better in snow, all-terrain tires or mud-terrain tires? If you can only afford one set of tires, yet you travel on snowy roads and also on snowy off-highway trails, this is a major issue. To answer this question, we spent a significant amount of time last winter swapping between a set of Pro Comp All-Terrain tires and a set of Pro Comp Mud-Terrain tires. Each Monday morning during the cold, snowy months of January and February, we'd fire up the garage heater in our Illinois Midwest Bureau complex, break out the tools, and swap our Jeep TJ test mule from one type of tire to the other, drive it for a week, then swap 'em back on the next Monday.
Each set of tires measured 31x10.50R15, and all were mounted on 15x7 rims. Of course, we began this test with no clue as to which tires would end up being the most effective overall. We also began the test with small arm muscles. By the time the eight-week test was complete, we had formed an opinion about which tire worked best for us, and we actually had some muscles on our carpal tunnel-riddled arms.
Some things didn't surprise us, like the A/Ts' excellent road manners and traction on snow-covered roads. On plowed but snow-covered roads, the A/Ts offered enough rear-wheel traction to allow our TJ to quickly accelerate across from a stop without the need to shift into four-wheel drive. When we did shift into 4-High, the tires helped to offer premium traction that allowed us to accelerate briskly and confidently into traffic, and often we could see thousands of small chunks of snow fly high into the air as the A/Ts did a respectable job of shedding the snow from the tread. When cornering, the interlocking shoulder-lug design helped provide excellent, grippy turns as long as we followed simple snow-driving rules and stayed off the brakes. At highway speeds the soft dual-compound rubber and flexible sidewalls of the A/Ts soaked up road imperfections, thus helping the contact patch stay glued to the highway for a reassuring feel on the snow at highway speeds.
Our first drive on the highway with the M/Ts changed the way we look at semi-aggressive tires on snowy roads. Some aggressive tires require a significant amount of give and take on the road-often more give than take-and this translates to road wander, fishtailing and a rough ride. The advent of the computer-designed mud tire, new rubber compounds and special tread treatments have all culminated in helping to create a much more civilized mud tire like the Pro Comp M/T. This civility was demonstrated repeatedly in a variety of snow types and depths as we used them to commute on the road.
While creating a firmer ride than the A/Ts, the M/Ts didn't exhibit a knot-in-your-stomach feeling of borderline control at highway speed. In fact, other than the firm ride (and more noise), they didn't exhibit much difference in overall liveability than the A/Ts did at highway speed as they bit into the snow-covered highway. Cornering was surprisingly grippy, even with the bigger, unsiped shoulder lugs, and the M/Ts threw large chunks of snow past our windows as the tread purged itself of snow just as it would mud. The M/Ts did lose traction a bit faster than the A/Ts when we wanted to use two-wheel drive to accelerate across busy snow-covered roads. This is to be expected, because all tires are biased toward the best performance in one particular area. In this case, the culprit may be the designed-for-mud high-void open-lug design, which creates a smaller overall contact patch than the A/T provides. It wasn't a significant problem however, thanks to the extensive traction-inducing siping on the center lugs of the M/T. A simple pull of the transfer-case shifter into four-wheel drive solved the tire slippage problem, helping to ensure jackrabbit starts into traffic, even on the slipperiest of surfaces.
Off-highway, the A/Ts really surprised us with their overall versatility. On a jaunt through 8 inches of snow at highway tire pressure with the TJ in four-wheel drive, they nimbly pulled the truck almost everywhere we wanted to go, cleaning themselves remarkably well as we progressed. We used them numerous times when plowing snow, and found that even fully aired up, they performed exceptionally well, with virtually no wheelspin, even when pushing a significant amount of snow. At 15 psi, their footprint widened nicely and this enhanced traction to create an even more capable tire.
The A/Ts' undoing, meanwhile, came when we encountered the greasy mud under the snow. Since they're not designed to be a mud tire, they loaded up relatively quickly and lost traction. Another obstacle that stopped the A/Ts was a grass hillclimb covered in about 4 inches of snow. Once they dug through the snow, they just didn't have the aggressive tread needed to bite into the slick grass and pull the Jeep forward. The M/Ts, on the other hand, seemed to do everything right off-highway. They pulled, pushed, dug, cleaned and generally impressed us with their capabilities. When we couldn't climb to the crest of the snowy hillclimb, we simply aired them down to about 15 psi and they clawed their way to the top. Even with a stiffer sidewall, they bulged nicely, and this put their shoulder lugs fully in contact with the ground for even more traction.
So what's the verdict? Would A/Ts or M/Ts be better for you? Well, you have to answer that question depending on the type of driving you do and what type of performance you wish out of your vehicle, both on- and off-road. We know many experienced 'wheelers who are extremely opinionated on this topic, yet offer completely different views regarding what type and brand of tires work best both on and off the snowy trail. Much of this depends on what the vehicle is, and how it's modified. We've been on winter trail runs where drivers take into consideration the forecast high temperature of the day, the snow consistency and the snow depth before choosing their type of tire for the trail. If someone held a bag of deep-fried pork rinds to our heads and demanded a one-or-the-other decision, our opinion is that based on this test, if we only had enough money for one type of tire on our jack-of-all-trades TJ, we would choose the M/T. We'll tolerate the minimal inconvenience of the M/Ts firmer ride and incrased road noise to benefit from their aggressive off-highway capabilities.
A closer look at the Pro Comp All Terrain and Pro Comp Mud Terrain
The Pro Comp Radial All Terrain features advanced tread technology that includes elliptical full-depth siping patterns throughout the tread that provide hundreds of biting edges for excellent all-weather traction. The A/T's variable-pitch lug pattern contributes to its classification as a Severe-Weather-rated tire. The new 50-state Severe-Weather rating is a relatively new addition to the tire-grading regulations, and this process measures the tires performance in snow and ice and replaces the old M&S (mud and snow) rating. This rating will get you past all but the most strict chain requirements. The A/T boasts a 50,000-mile tread-life warranty. The tire is constructed of two polyester body plies combined with a blend of dual sidewall rubber for maximum puncture resistance.
The Pro Comp Radial Mud Terrain features a Twin Rib Center Traction Zone that consists of interlocking, open, aggressive twin high-void lugs that deliver superior traction. The 90-degree checked siping pattern increases and maximizes wet-weather traction and bite on rocks and hard surfaces. The shoulder lugs are predrilled for studs for driving in ice and snow, and the M/T's shoulder corner lug treatments add a deep traction bar styling that also maximizes the biting edge for increased traction in rocks and mud. The polyester body plies consist of thick two-ply construction combined with a blend of dual sidewall rubber, which allows for maximum puncture resistance with total flexibility when using low off-highway air pressure without the heat build up.