At first we were a bit concerned when Mickey Thompson Performance Tires & Wheels became part of the far larger Cooper Tires, the eighth largest (in sales) tire company in the U.S. for the past few years. So much for seeing any more small-volume enthusiast tires, we thought. Luckily, we were completely wrong, and Mickey Thompson keeps cranking out specialty tires-except of much better quality.
In the case of the Baja ATZ, small volume only refers to the relatively small numbers of tires made (compared to the enormous amounts of passenger-car tires sold in the U.S.), as the smallest ATZ at this writing was a 33x15.50R15. That may not sound all that large, but this was the first 33-incher that rubbed the fenders of our test Blazer-which normally allows 35s to fit comfortably.
With a section width of 15.7 inches and a tread 12.1 inches wide, the 15x10-inch Classic Lock II wheels we used are technically too narrow for the tire, but handling was still very good, and the tracking we had anticipated was practically nonexistent. Besides, with 12-inch rims the tires would've really rubbed. There was more tire noise than expected, but the ATZ is by no means a loud tire. It's just that with four patches over a foot wide each, there are a lot of tread blocks hitting the ground at once, and it's enough to be audible. Yet the rolling resistance was relatively low.
With a high load-carrying capability (2,405 pounds at 35 psi) and a nylon cap over two steel belts, the tire still soaks up irregularities in the road pretty well, and made in a 12-segment mold, it runs very true and smooth. On the Hunter GSP 9700 balancer, we saw very low Road Force Variation numbers (8, 15, 12, and 14 pounds), which is especially impressive on a wide tire weighing 83 pounds. This says a lot about the build quality of the tire, and the trueness of the Classic Lock II wheels. Those 'locks, by the way, are a purely cosmetic add-on, but since they're available separately, they can be used as sacrificial rim edges. The wheels themselves are guaranteed against structural defects and have steel inserts for the lug nuts to spread the clamping load through.
We expected the 12.1-inch-wide tread to do pretty well in sand, and it did. However, airing down to a conservative 10 psi apparently made the stiff-treaded radial push so much sand ahead of itself that we aired back up again-the price you sometimes pay for running a radial with good road manners. In harder dirt, a lower pressure allows the Sidebiter lugs on the sidewall to help with traction, and conformability improved to the point that fist-sized rocks were barely noticeable.
Great for traversing ruts, the width of the ATZ works for or against you, depending on the situation on hand, and the vehicle. Our portly test vehicle put enough contact pressure on the relatively mild tread to make it work in the dirt, but on a lighter rig, the more aggressive MTZ would be a better choice. The same would hold true for mud, of course, but we didn't have any to try the ATZs in.
We feel that the Mickey Thompson ATZ is a tire primarily for the street that works well on the trail under a heavier vehicle, but between the stiff tread area (which makes it perform on pavement) and it being a radial, it's not something we'd put on a trail-only vehicle. Now, if you'll excuse us, we'll go cut some more sheetmetal off the fenders on our mostly-street four-by so that these tires won't rub as often.
Tire: Mickey Thompson Baja ATZ
Load range: C
Max load (lb. @ psi): 2,405 @ 35
Sidewall: Three-ply polyester
Tread: Three-ply polyester, two-ply steel, one-ply nylon
Approved rim (in.): 11-13
Tread depth (in.): 20.5/32
Tread width (in.): 12.1
Section width (in.): 15.7
Overall diameter (in.): 32.9
Static loaded radius (in.): N/A
Revs per mile: N/A
Weight (lb.): 83
Test vehicle/weight (lb.): K-5 Blazer/6,300
Mickey Thompson Performance Tires & Wheels