Tires: Mild Dry rot, tires continental, tongue weight

Question
Bought a Ford Expedition new in 04 and still running the original tires, Continental Conti Tracs. At 70k miles they look great, never rotated, never balanced and the ride is almost as smooth as new. I have noticed some very light cracking about 2" from the bead and I just bought a 6000# travel Trailer with about 700# of tongue weight. Should I stop being so cheap and replace all 4? They probably have 8/32's of tread left.

Answer
Paul,

Your tires are 7 years old.

Recent bulletins from the tire industry indicate that tires degrade simply due to time.  The age of a tire is important even if the tire is unused.  There some disagreement over how to best express this age limitation, but my take is:

If you live in a hot climate (AZ, CA, NV, TX, and FL) then the limit is six years.  If you live in a cold climate (MN, ND, WI, MT, etc), then the limit is 10 years.  States in between are  ..... ah ........ in between.

So depending on where you live, you could have crossed that line.

But since you have cracking - which is a good indicator that there is something bad going on - plus you know you are going to be asking more of your tires - it sounds like you only need a bit of persuasion.

So if I say change them, will you do it?