I have a 2006 Mazda 3i touring w/ 205-55R16 Toyo Proxes tires. We purchased the car new and it now has 17,600 miles and was informed while the car was in for service that all 4 tires are cupped. The tires were nitro filled when new and are consistently checked for proper pressure, the tires are rotated every 6500 miles and the alignment has been checked and is within spec. Mazda says this is normal, everyone else says its is not - I am curious to know what everyone's thoughts are about this, sure doesnt seem normal to be - this is an economy car and should get more than 17K out of tires. 90% of the miles are highway and the car is not abused.