Tires and Wheels problem
2004 Toyota Solara 6 cyl Front Wheel Drive Automatic 95000 miles
Ever since I have had my car the rear tires cup on the inside. I first noticed it on the original 17" Bridgestones that came on the car, and I have had two sets of Falkens. The tires show visible cupping at 10k, and the road noise increases. I have unidirectional tires for better performance. I rotate the tires and even remove them from the rims swap them so the inside is now on the outside to extend the tire life. I end up buying new tires between 20k & 25k. I also buy snow tires during the winter.
I have taken it to the dealer and all they do is bounce it up and down and say the suspension looks good. I had them check the alignment front and rear on two separate occasions adjusting as needed to the factory specs. I mentioned my problem out of frustration to my tire dealer and he suggested new struts.
I don't mind putting in new struts if it solves my problem, but I would hate to think of spending additional funds in this economy if it is not necessary.
Directional tires generally are performance tires. Performance tires have a softer compound than other tires. This means that they grab the road better. BUT it also means that they wear out much faster than regular passenger tires. Also, any suspension issue will be magnified with preformance tires.(Race cars have a type of performance tire on them - that is why they change them every pit stop)
Even if your suspension was perfect (which it does not seem to be) performance tires will wear out way before regular tires. Now to the issue with the cupping. By cupping on the inside -- do you mean wearing out evenly - or actually cupping which looks like there are chunks of tread " cupped" off the tire.
Cupping is almost always a shock and/or strut problem. However, it is could also be a tire out of ballance. Being that you say that you remove the tires from the rims when you rotate them -- make sure that the tires and ALWAYS high speed ballanced every time that they are removed from the rim.
BTW -- cupping is the result of the tire " bouncing" beyond the control or without the control of the suspension.