Our new Michelins were almost 5 months old when we had them installed last year. I'm OK with less than 6 months. I would love to have one week old tires but it didn't happen. LOL!
When we bought in May, they had tires made in 2012.... I said no, I want them all manufactured in 2013 which is what I got. I knew I was going to sell the coach this year (2014) and wanted to basically state that the tires had 2013 date codes.
Safe travels,
MM.