I also questioned your lowering the air pressure on a hot tire. tires pressure will increase as you drive and you should not lower the air pressure unless the tire pressure is high during a cold test not a hot test. rise in temp during a drive is normal. I bought a used TT last year and bought new over sized Carlisle tires and have had no problems with them either. One thing I've learned by selling TT's is the manufactures put the lowest rated tires on their units. that is why I went to a larger tire with a larger weight rating.