Need new tires, old tires never rotated

Check the DOT code for tire age. Some consider 6+ years as the safe age limit when driving at high speeds.

 

I second Mendel Leisk skepticism on the "like new" condition of the rears, but I'll take your words for it. Though I would rotate them left/right, now and before the trip, to reverse some of the only directional wear over the years and 48k being in one spot.

I would make the same decision as you IFF the rears are in as good conditions as you said AND IF i'm driving the car locally. I wouldn't be comfortable for any of my loved one to drive on tires that are more than 6 years old though, regardless of treads.

 

FWIW, we're STILL rolling on Michelin Pilots manufactured in Feb of 2009. Lots of tread still, regularly rotated. There's some fine cracking in the tread grooves, keeping an eye on it.