Never taken spare off truck...

Tires for most people should be replaced every 6-7 years regardless of the tread. Yes, it is sunlight and heat that breaks down the rubber so the 6-7 year number isn't carved in stone. If you live in Florida, Arizona, or other hot sunny state and your vehicle is stored outside in the sun then 6-7 years is old enough. If you live in northern latitude and your vehicle sees less sunlight, then you might still be OK up to 10 years. But 10 years is a hard line for me. Even for the spare.

I wouldn't rush out and buy another tire for a spare. Although you should be able to find a much newer used tire and have it mounted for under $50 if it makes you feel better. I would rotate one of the tires currently on the ground to the spare the next time you buy tires however. I do that every time I buy new tires.

 

I replaced the original unused spare in my 06 at 13 years old. I dropped it to install a new TPMS module and when breaking the bead the sidewall started cracking. There were cracks in the tread also. It still held air but was not safe in my opinion.
I inspected the unused BFG replacement recently and it was developing small sidewall cracks. I'll replace in the next year or two. Must be the Florida heat.

 

I replace my spare every eight years with a tire of the same size, usually the cheapest AT I can find.

They absolutely do rot under there.

 

Could do a 5-wheel rotation Jeep style.

This is the one I do.



Then you know your spare is in good shape

 

This is something you would have to do yourself because the dealer or tire shop will never do, too much effort for them.

I used to mark my tires for when I would swap out my summer and winter wheels, and you would be surprised, or maybe not, how many times after telling me they did a tire rotation they actually didn’t.

 

I too have never used/accessed my spare tire on my 2015 TRD Sport.

I have since upgraded to new wheels and bigger tires.
At some point I'd like to replace the factory spare with a full size spare tire/wheel.

What is the largest size tire that can fit on a factory spare wheel?

 

100%. The shop I go to will if I throw the spare in the bed, but dropping and re-raising it under there - doubt it. I just do it at home. You'll need to reprogram the TPMS as well, at least in my 2020. I have the pressure readout on the dash, but I don't think the TPMS system looks for the spare at all on second or turd gens.

 

I too am one of those who kind of ignored the spare, not that I didn't know any better, I just did. My spare was never used and at the last tire purchase, I had the tire shop put the best of the old, on as a spare even though the spare was like new. I felt it was better to have an old almost worn-out tread life tire on than a never-used new 11-year-old tire for a spare. I had no trouble getting the tire down, but I did coat the chain, the lifting mechanism, and the steel wheel exposed to the elements with Woolwax, Fluid Film, or Blaster Surface shield, whatever I had on hand before I put the tire in its place.

 

Used to keep the spare underneth... this mod made lowering alot easier.
https://www.tacomaworld.com/threads/cheap-free-mods.4838/page-51#post-3571643

 

Well, got the (2012) spare out, gave it a wash, and checked pressure, still had 8 psi.

My plan is prep this for now, 35-40 psi, observe pressure for a few days. Later I will get a used rim and cheap 245/75 R16.

 

you should drop it once to familiarize yourself with the process. on my 2006, I flipped the spare over so I could easily access the air nipple to check it periodically, or fill it up when the TPMS lights up.

 

An inflated tire blowing out in the cabin can/will kill you. Happened to my grandparents' friends - not something you'd expect to kill you. Didn't even physically hit them, it was the instantaneous pressure increase.

 

I was getting new tires on my 2008 a few months ago and pulled the spare down to look at it. The tire was holding the air but looked it had some dry rot on it. Didn't want to take a chance so went ahead and got a new tire for the spare. Got something that wasn't as expensive as the new tires. Just with the better to be safe than sorry philosophy...

 

A good friend of mine from HS had one of those old two-door Tahoes with the spare that you keep inside the cab. He got rear-ended by a dump truck, the thing broke off its carrier and hit him so hard he has brain damage.

 

Yikes, I forgot about those. That's terrible!

This one was just sitting still - they pulled it off and put the spare on because the sidewall had a big bulge, and for whatever reason they threw it in the back seat rather than the trunk. They stopped at a gas station or something and it let go. It may have been just the guy's wife or girlfriend that was in the back with it (windows up) but it's been many years since I heard the story. Either way - definitely keep sus tires out of the interior unless you let the pressure out...

 

Yup. People always forget (or simply have no idea) just how much raw energy is stored in a few gallons' worth of air compressed to 35psi. Plenty to cause lots of damage, especially to meatbags, when released all at once. I also cringe and/or GTFO when I see a rusted (or worse, sloppily welded/"repaired") air tank.

Hence my above comments. I've been known to use tires well past their suggested expiration dates, but the second I see cracking or any reason to believe the structure is compromised, it's done.

 

I had a flat 2 weeks ago and lowered my spare from 2014 just fine, it wasn't flat but down to 12ish psi. still holding air 2 weeks later

 

It looks like my 2012 spare is not holding pressure - tire leak or rim corrosion?
So now looking for used tire/wheel combo locally.
Possibly local junkyard, or even from forum member in Eastern MA.

 

Never touched or lowered the spare on my 2013. (on my third set of tires) This thread is a good reason to check it now - thanks!!

 

probably worthwhile to soak the whole thing with soapy water and isolate the leak before trying to buy a new/used wheel/tire.

If it’s a bead leak on a corroded rim you can take the tire off and clean it up with some sandpaper or steel wool. Maybe put a new valve stem in for good measure, they’re cheap since the spare doesn’t need a tpms sensor. If it’s the tire leaking, It’s already toast so just get a new tire (same size as your others). Either way you’ll be good as new and save a few bucks.

Or take the chance to splurge on a new set of tires if it’s warranted, and keep the best one as a spare.