Tire age

There are posts on FABO and FBBO about this. I go 7 years and that's it. If I am on the road I want to be as safe as possible. What freaked me out, I was running my '93 Subaru Legacy in the left lane of the interstate at 80-85 with 12 year old tires! I wasn't paying attention. Think of this: even at 40 MPH you have a flat. There are roads without shoulders. If you have a flat on the left you need to change your tire exposed to traffic.