This will highly depend on the surface you drive on and compound of rubber you get. Most of the time, MT tires are what we would call "medium" in racing, and are most often in grass or softer dirt, rather than on high bite abrasive surfaces like sugar tracks. Running in gravel will be similar to the soft stuff too, as the tire will throw it more than rub against it. If you decide to do a lot of parking lot running, then you might still wear them down quickly, but otherwise, not so much.