We have two cars that are each driven about 4,000 miles a year. Since it will take 10 years or so to put 40,000 miles on the tires, should I consider replacing them after a certain number of years, instead of miles? If so, how many years do you recommend for replacement?
-- Bob
Well, the American tire industry recommends that tires be replaced every six years, even if the tread is not worn down. Of course, the American Couch Association also recommends that you replace your sofa cushions every three months due to flatulence. And I think both of those industries probably are erring on the side of caution. And increased sales.
Tires do dry out and degrade over time, due to exposure to sun and ozone in the air. I'm sure you've seen old tires that are covered in small cracks on the sidewalls. Those should be replaced.
They also can degrade in and around the tread, where most people don't look. So that needs to be checked, too.
So my advice would be, starting at year six, have a mechanic you trust (and not necessarily a tire salesman) take a good look at your tires. You need a knowledgeable, non-interested party to do a visual inspection and tell you whether the tires are still good.
If your cars sit outside all the time and you live in a hot-weather climate, and you bought cheap tires to begin with, you may need tires after six years. If they're garaged, or they're particularly good tires, you could get seven, eight or even more years out of them while still driving safely.
And you want to factor in your driving habits, too. If 95 percent of your driving is from your house in a golf community to the clubhouse for lunch and back, the risk of catastrophic failure is low, because heat from high-speed driving is what tends to make tires fail suddenly.
Whereas, if you do a lot of highway driving, you'll want to err on the side of caution and make sure your tires are not near the end of their lives.
By the way, if you're not sure how old your tires are, you can check the sidewall. You'll find a number there that says something like "2214." That means your tires were manufactured during the 22nd week of 2014.
And if they're not 6 years old yet, at least you'll know when to throw them their next birthday party.
I bought a 15 year old travel trailer last summer. The dealership gave it a full inspection and fixed a few minor issues, but the subject of tires came up only as a mention of the remaining tread wear, which was ample. The expired registration indicated this trailer hadn't been anywhere in three years. Wear and tear elsewhere indicate that the trailer had probably been used very little. On our second weekend outing, we had been parked and set up for a full day when that morning there was a loud pop. Investigating, we discovered a HUGE blowout in the TREAD of the tire, and happened to be right on top as the tire sat. It appeared to be a tread separation failure. Decoding the DOT markings, the tires dated to having been the OEM tires that came with the trailer 15 years earlier (including the spare). It was fortunate that we weren't doing 65 on the freeway when this happened. I limped home on back roads never exceeding 40 MPH, stopped every 10 miles to check, made it home safely, and bought a new set of tires Monday morning. We don't put a lot of miles on our trailer, so I suspect these tires will still LOOK perfect 10 years from now, but now I know (the hard way) not to go longer than that.
I'm surprised at this answer, because it passes over a reason for not using old tires that Car Talk has addressed previously: stickiness. Compare the eraser on a brand new pencil to the one on a pencil that's been at the back of the junk drawer, unused, for 20 years. Tires are not, of course, quite the same thing, but the same happens to them, and it makes them less effective at gripping the road... and it happens mainly as a function of time, however they may be stored. It's why you don't want to buy tires that were made a few years before, even if they're apparently brand new.
10 years would be my max unless used on low-speed roads A car stored in the garage out of the sun will do better than tires on one parked outside all the time.
The date code may only be on one side of the tires. I have some that I thought didn't have a date code but noticed it on the inside of the tire when I was doing some work. If you can't find a code, it is likely on the inside part of the tire. These are not directional tires but don't know if a directional tire would have it on both sides or not.
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