When was the last time you checked your tire pressure prior to this? Whatever that tire place was talking about a heat ring, thats a bunch of hooplah. Riding the tire on the sidewall weakens the lining inside, its dangerous and can result in a blowout at high speed. As far as the pressure loss issue, I have no info on that, unless you contact Continental directly and find out wit the DOT number on the tire. The dealer won't do anything because tires aren't warranted since they're wear and tear. Now buying a different new tire isn't advisable either. You gotta match the treadwear, traction, temperature, and speed rating. It can handle differently from the other Contis on the car as well.