Your tires withstand a massive amount of general wear and tear due to the amount of contact and friction that they have with the road. Over time, there are a number of different wear patterns that can begin to develop. Irregular wear patterns can be a symptom of a more serious problem with your car, and so understanding how to read tire wear can help you diagnose and fix car problems before they become more complex and expensive to fix.
Feathered tire wear refers to when the treads of a tire are worn so that one side is smooth, while the other is less worn down and has a sharper edge to it. This can often be seen by eye or can be easily felt by running your hand over the treads of your tire. This is different from uneven or one-sided wear, as both sides of the tire are worn down, but they are worn to a different finish (one side is smoothed, the other sharpened). This occurs due to alignment problems, either because your tires are facing toward or away from each other or because they are improperly mounted on your car's rims, and you should see a mechanic to have either of these issues addressed.
Even tire wear refers to when the entire tire wears down at an equal rate, creating a smooth surface at all times of the tire's lifespan. Uneven wear occurs when either the middle portion of your tire or the outside section has become significantly more worn. If the middle of your tires are extremely worn down while the outside treads are still in good condition, your tires are overinflated and need to have the air pressure reduced. If both shoulders of your tire are worn away with an untouched center, you do not have adequate air pressure within your tires and need to have them inflated.
One-sided tear wear is slightly different from uneven tire wear and represents an entirely different problem. One-sided wear occurs when one shoulder of your tire is worn down at a greater rate than the other. This happens when your tires are cambered, or leaned, to the side. Excessive wear on the interior shoulder means that your tires are leaning in toward the body of your vehicle, while wear on the exterior shoulder represents the fact that your tires are leaning away from your vehicle. In order to fix this, you should see a mechanic such as XL Auto Service & Tires immediately to have the alignment of your tires adjusted.