Tires: tires cupping, Tire Cupping

Question
I own a 2008 scion xd. My problem is all 4 of my tires are cupping. The Toyota dealership is telling me that its the tires. Could it be the tires or could it be bad shocks like i keep reading on line about. Could something else be wrong with the car.

Answer
Brian,

While technically cupping is caused by bad shocks or out of balance tires, the term is used incorrectly, where "irregular wear" would be more accurate.

Irregular wear is caused by misalignment and aggravated by insufficient inflation pressure and insufficient rotation practices.

So a check of the alignment is in order.  BTW, most factory alignment tolerances are too wide by half.  So if the dealer is doing the alignment, you should insist the alignment be within the inner half of the tolerance - and don't accept "there is no adjustment" as an excuse.  They make eccentric bolts and camber kits just for that purpose.