Weekend Off-Roader 80% Road & Sand, 20% Dirt & Mud The STZ is the latest all-terrain design from Mickey Thompson and introduces many new modern features. The new tread pattern design offers excellent steering response, superior grip and more traction, making it the perfect choice for work or play. The Baja STZ is an excellent choice as an original equipment replacement tyre and is available in light truck sizes with increased load ratings. Extra Protective Layer An extra nylon belt (in most light truck sizes) is laid between the tread and the steel belts to add strength. It also reduces moisture transfer into the steel belts, a common cause of delamination through cuts and drilling.