I never even knew this existed until now...

I found a set of brand new Mickey Thompson ET streets for the Colt on Kijiji. Everything looked good, stickers in place, little hairs on the rubber, greasy coating from proper storage. For the price we settled on I couldn't say no.

I brought them home and that's when I learned about the tire manufactured date stamped on every tire! How have a not heard of this before? I went to the garage to see just how new these new tires were... 23rd week of 2009! Yup, my brand new tires are actually 6 years old! I mean, they were properly stored and still have that greasy coat on them, but I'm wondering if this date is a cause for concern?

Would you guys still run them?

5-7 years is the age limit for most tires. For something like a mikey thompson with super soft compound they will not be as sticky as they were before. Also how they were stored will make a huge difference on how they are going to be.

This is a good read.
http://www.wheels.ca/news/tire-talk-how-old-is-too-old-for-tires/

They were stored in doors and out of the elements, that's all I know. Still very soft and pliable, they have a greasy film on them as well in and out. They seem perfectly fine except for the manufactured date.

They should be fine. Use them.

Ghislain

Pretty sure that legally, tires can only be sold as new, up to 6 years after manufacture date.

Selling used off a vehicle, there is no law in place from what I know.

Selling used on a vehicle AND to pass safety, they must meet minimum road worthiness standards - doesn't appear your tires have "obvious issues" to meet ineligibility for use on public roadways.

If as Ghislain mentioned, they appear fine and continue to look fine after driving, they may hold up.

I have 14" tires sitting in storage now, nearing a decade old and they look fine.

I retire lots of tires from 3-9 years old at work, because of excessive cracking between the tread blocks and down the sipes, or worse yet, to the cords in the sidewalls (damage usually more than cracks in that regard).