Dick, I don't have the tire seminar experience, but I have had two tires blow on my previous coach. I bought a 2001 Discovery in 2005 with less than 10,000 miles on it. In 2007, I loaned it to my son to take his family, and very pregnant wife, to a funeral in Kansas City. (she was too far along to fly). On the way, he had the left steer tire blow on the interstate, which cost over $2000 to replace the tire and repair the damge to the air brake lines and fender area. On the way home, a rear dual blew, that one did no real damage, but when he called and asked what to do, I had him replace all the rest. We inspected those tires before he left, and found no cracks or checks, yet they were obviously dry-rotted. My tires on the Beaver are dated 2006, have 40K on them and look like new. I store it inside a barn, out of the sun, but still worry everytime we use it. I have actually already replaced the steer tires due to uneven wear caused by an alignment problem, but will replace all of them before our trip next summer.
I consider my son very fortunate that he was able to control the Discovery when it blew the steer tire. He's a good driver, and traffic was light. He still said that it took 5 minutes after he got it stopped before his rear end released the seat. The cost of the new tires is far outweighed by the possible cost of a blow-out. Since then, I've had problems on two seperate trailers with tires that looked fine, were properly inflated, but failed. One blew, ripping the fender off the trailer ( I didn't even know it was gone until a passing motorist flagged me down. It was a light trailer with the golf car on it), and the other threw a chunck of tread about the size of a football. I now replace every tire on every trailer when it gets to be 5 years old, regardless of how it looks.
