Are cupping and feathering the same thing and are they both caused by bad shocks?
They are different things . Put ( tire cupping and feathering ) in your search engine and you will find actual article and videos that explain what they are and yes the suspension causes cupping an is not safe.
Feathering is the wear on the outside edge of the tire that feels smoother in one direction and rougher the other way. Some cars will have that before 3,000 miles and others might wait years to show it. It likes to happen on non-driven wheels. Cupping is flat or concave places around the tire and is a sign of a serious problem.
Both could be caused by shock problems, but usually feathering is a result of either incorrect toe (i.e. faulty wheel alignment) or driving style, such as aggressive cornering. Both problems can be mitigated by frequently rotating the tires.
Both cupping and feathering are frequently used (incorrectly) to cover a wide range of situations - some of which are caused by bad shocks.
I won’t go into the exact definition of those 2 terms - except to say that feathering refers to a thin flap of rubber (a feather) and cupping refers to a gouged out area of the tread that looks like someone used a cup to scoop some of the tread out. You rarely see either of those nowadays.
Thank you everyone for the info - i did read up on it and watched some videos prior to me going in so i could talk intelligently to the mechanic! :o)
I needed struts and an alignment along with new tires - i can tell the difference already! Much safer on the road.
Be safe and have a blessed day