Tire age / "dry rotting"
 

I have a set of stock Rubicon tires that are ready to be replaced. However, my spare tire has never been used - and I'm wondering if it would be fine to start using it, and just buy 3 new tires, instead of 4. And then I'd just use one of my worn-out tires as a spare.

The spare is probably 3-4 years old (I bought these wheels/tires used, so I'm not totally sure) - and it looks perfectly fine - but I've heard that tires tend to break down over time, from being in the sun, and also from just drying out (the rubber compounds loose their "sticky-ness", so traction isn't as good?).

Thanks for any input!

Check the DOT on the tire. The last four numbers are the weeks and year of production.

Example... DOT NT85S214T2207 22 is twenty second week of 2007

If the tire is 3-4 years old your fine. Industry standard is 10 years but I myself wouldn't push it more than 8. Check for "Dry Rot/Cracking" or any obvious wear/breakdown of the rubber due to weather or chemicals such as Armor All. If all checks out ok you'll be fine. Any questions feel free to PM me.

I believe a tire 6 years or older is considered out date whether its used or not.

Honostly, I personnaly wouldn't worry about it. It's a light vehicle as long as there is no evidence of splitting. I would have no problems running that tire. And if it did I'ld just run it on the back. Anytime I've seen a dry rot tire give up the ghost it was after it sat for a while and slowely leaked out. It could use be refilled and run few more days till refill again.

I agree with the 6 year limit, I have made it on a 25 year old spare. I also had a 15 year old spare IN THE BACK OF THE XJ blow out and it hadn't been on the ground in years.

Tires are like women, you never know when they will blow.:D

True for some but not all. Michelin and Kumho for example have 80-100,000 mile rated tires that they stamp with a 72-84 month warranty but for your typical M/T I agree...6 years safely. I get guy's in the shop all the time wanting there 8-10 year old spare put on and I won't do it. I had a 8 year old Goodyear blow on a customer in my parking lot just shortly after installing it and airing it back to 35 psi. It looked brand new.

If the tire looks okay. I would try it on the rear to start out.

Good Luck
Nick

Thanks for all of the responses, good info. I checked the date on my spare tire - turns out the tire is actually 7 years old. I thought it was only 3-4 years old, so good thing I checked! So I think I'm going to keep that tire as my spare, and just buy 4 new tires.