An average driver has one set of all-purpose, all-season tires. A person who's extremely into his or her cars might have up to four sets. You could have your regular tires, your track tires, your winter tires, and if you own an off-roading vehicle, mudding tires. Maybe you even own slicks. The point is, if you have this many tires but don't want to purchase rims for every set of rubber, you're going to need to learn how to change out the actual tire. Having to take it into Discount Tire all the time would be annoying, so you might as well just add this piece of machinery to your three-car garage.