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View Full Version : How old before car tires are unsafe?


The Controvert
05-04-2005, 06:14 PM
I went to Firestone today for an oil change and they wanted me to buy new tires. They pointed out some minor cracks in the grooves in my tread and called it "tire rot". They implied that the tires are old and unsafe.

My car is 5 years old, but has been driven only 11000 miles. There appears to be enough tread left on the tires. Is Firestone trying to sell me new tires I don't need?

Uvula Donor
05-04-2005, 06:39 PM
Once upon a time, I had a Ford Fiesta (the little German-made one from the '70's.) I took it to a local Firestone garage for tires. While I was waiting, the Service Manager came out and somberly informed me that my front struts were "leaking" and it was causing a "dangerous situation." I needed to have them changed right away. Right then, in fact. He brought me out to the service bay and showed me the reddish fluid dripping down the sides of the struts. When I told him I just wanted the tires put on and I'd arrange for service later, he told me that he couldn't release the car to me in that condition because it was unsafe, and he'd have to call the Registry of Motor Vehicles and have an inspector come by to take the car off the road.

I told him while he was on the phone to call his lawyer, and maybe an ambulance, because I was leaving WITH MY CAR.

They put the tires on, I paid for them, and left.

The oil dripping from my struts was bright red clean new tranny fluid they had squirted onto the struts, not the road-dirty fluid one would expect that would be clinging to an undercar part.

Two months ago, the shop where I work took the brand-new company van to a different Firestone shop for a routine oil change. We were informed by the Firestone shop that the front ball joints were bad and needed to be replaced, and they wanted a purchase order number for billing.

The boss got on the line and told them that since it was a new vehicle under warrantee, we'd have the dealer do the ball joints, thanks. Of course, there was nothing wrong with the front end at all.

So...you can probably guess what I think of Firestone and their ethical practices. I'd take the car somewhere else - like your regular mechanic if you have one - and ask for an unbiased opinion.

Mr. Slant
05-04-2005, 06:40 PM
The term is "dry rot". Tires with high years and low mileage will occasionally experience this. 11,000 miles and 5 years would probably qualify.
Granted, service writers are sometimes thieves, but sometimes they tell you about purchases you really should be making.
I had a car with dry rotted tires, and experienced tread separation during a complicated and stressful passing maneuver.
Typically tires will make it a little longer than 5 years, though, with 10 being closer to the accepted maximum.
If your tire really is experiencing visible dry rot, you would want to replace it.
I have seen numerous automotive journalist indicate that tires experience a change in performance around the 5 year point, becoming less "rubbery" and more rigid, which would negatively impact handling and ride.

TheLoadedDog
05-04-2005, 06:42 PM
They might be telling the truth.

Tyres "vulcanise" and get hard with age. I have heard that four years is about the safe limit for a tyre to be used, regardless of tread wear. Sorry, no cite for that - it's just one of those factoids bouncing around in my head.

I'd second the option of getting another mechanic to check it out.

Mr. Slant
05-04-2005, 06:43 PM
Oh yeah, and Firestone may make good tires but their retail facilities do tend to seem like they're run by jerks.

Pullet
05-04-2005, 06:45 PM
If the car has been sitting around unused, the rubber could become useless before the tred is actually worn down. I've had this happen to my bike a lot.

Fun story: Some friends of mine bought a WWII era Jeep a few years ago as a fix-up project. The spare tire seemed to fully inflated, which was suspicious. The dropped it to check its bounce. It broke. The thing had petrified.

YMMV

Xema
05-04-2005, 08:23 PM
I'd be skeptical of someone claiming that a 5-year-old tire is too old and must be replaced. It's not impossible, but it's unlikely. If possible, take the car to someone who knows cars and doesn't sell tires, for an unbiased view.

danceswithcats
05-04-2005, 11:01 PM
Speaking as a former inspection mechanic, simple cracks wouldn't cause me to reject a tire. So long as cracks are small, and there is no evidence of belt separation, or other physical deformity of the tire, and the tread depth meets current requirements of the safety inspection document, I'd pass it. That would also be an educated choice based upon my knowledge of the owner and their driving habits.

That said, the NTSB conducted an investigation into two accidents involving 15 passenger vans which saw very little use. From the report: (http://ntsb.gov/publictn/2003/HAR0303.pdf)
Two of the Henrietta van's four tires, including the tire that suffered tread/belt separation, were original tires (8 years old). Three of the four tires on the Randleman van were more than 8 years old. When not in use, both vans had been parked in the unprotected parking lots of their respective shurches since purchase. The tires were subject to ozone and ultraviolet light present outdoors, which can degrade the tire rubber, leading to dry rot and weather checking. These phenomena are typical of a sedentary vehicle; during normal use, anti-degredants introduced during the tire manufacturing process are released and brought to the surface of the tire. When a vehicle is not driven extensively (the Henrietta van averaged 5,500 miles per year and the Randleman van averaged about 7,000 files per year), this release does not occur.

Cheesesteak
05-05-2005, 06:03 AM
You should do a detailed inspection of the tires yourself. Look at the tread, pick at the tire to see if the rubber is disintegrating. Check the sidewalls. Compare it to the tires on a similar car that is in good condition.

I recently changed my tires out because they were getting dry rot. The sidewalls were hazing, or had zillions of tiny cracks in it. I figured my safety was worth more than a couple hundred bucks, and I didn't want a tire failing while doing 70 on the highway. If I only drove it around town at 30, maybe I make a different choice.

spingears
05-05-2005, 07:40 AM
As far as tire wear goes a Lincoln penney is a simple gage. Insert the top of Lincoln's head into the thinnest part of the tread. If the top of his head is above the tread it is considered unsafe.

Auto service scams are perpetrated by unscrupulous service managers and/or their mechanics attempting to improve their bottom line. It is not the usual practice of "The Company."

critter42
05-05-2005, 10:23 AM
I had a similar experience as the OP, except it was at a Goodyear facility while I was on vacation, and I was there to have my front driver's side lugs replaced. I came out about 4am on the morning we were to leave for home and it was flat. I got the donut on and took it down to a 7-11 to fill the original tire up. I'm not sure why, as I've put and taken off dozens of tires/donuts in my life, but on this one 3 of the bolts would not come off, and on two of them the bolts sheared in half while trying to get them off. I limped to the Goodyear to have them replaced. Meanwhile they showed me the front tire I had removed and pointed out the reason why it was flat (even after I had aired it up, it was flat by the time we got to tire place) - I couldn't really hear any hissing, but he soaped up the inner sidewall and the sucker started making bubbles like crazy. The section of rubber around the Goodyear logo and text was cracked and was apparently cracked through in places. The crack was like an outline around the logo/text - almost like that wherever the tire had been molded to create the logo/lettering was weaker than the rest of the tire . He then pulled off the passenger side front tire and showed similar damage to that tire, although it had not made it completely through the sidewall yet.

He told me he had inspected the rear tires, but they looked really good (they should have - the rear tires were only about a year old, but the front tires were probably around 4 years old). He told me that I didn't need to replace all four tires, but in addition to the new front driver-side tire, I should replace the front passenger tire - not only because there was no telling when the passenger tire might go out, but that given the age/wear difference between the two tires (ie new on the driver's side but old on the passenger side), it could adversely affect the handling on the car or even cause the damage on the passenger side to accelerate. Since I had a 1000+ mile drive back home I decided not to gamble and had both front tires replaced. However, was the tire guy selling me a line? They came across as pretty honest, as I only paid the price listed on the in-store display, no stem charges, mounting balancing, etc, but I tend to be too cynical for my own good and still wonder if I bought something I didn't need. I guess my question is - if I only need to replace one tire, is it still recommended that I replace its opposite at the same time (my fronts and rears are different sizes, if that makes any difference)?

critter42

Cheesesteak
05-05-2005, 10:53 AM
I think you're being a bit too cynical, critter. There was visible damage on your already flattened tire, which was also seen on the not yet flat tire. Generally, it is better to replace both sides at the same time, especially if the tires are old. If the other tire is damaged to boot, I wouldn't hesitate a moment in replacing it.

Mathochist
05-05-2005, 11:05 AM
I guess my question is - if I only need to replace one tire, is it still recommended that I replace its opposite at the same time (my fronts and rears are different sizes, if that makes any difference)?

I hit a curb at a rest stop on the NJ turnpike a couple months ago. Cracked straight through the tire. Just last week, with my tax refund burning a hole in my pocket I ran out to replace my other three tires that really could have used it for some time. Sure enough, I had to get that other one replaced since in less than 2000 miles (I don't drive that much) it had some heavy alignment wear from not being paired up with a similar tire on the other side.

Mr. Slant
05-05-2005, 11:14 AM
SNIP
I guess my question is - if I only need to replace one tire, is it still recommended that I replace its opposite at the same time (my fronts and rears are different sizes, if that makes any difference)?

critter42

This is not a professional opinion, as I can only give those about computerized equipment.
I have always heard that your steering may be affected if you run unlike tires on the front. Seeing as you couldn't swap front to rear on your vehicle, I believe the Goodyear shop was giving you good advice.
My personal preference would be to minimize differences in grip by keeping the same make, model and mileage of tire on all wheels of a passenger car.
I'm not DOING THAT, personally, right now, but only for money reasons.

Notes

A journalist in the employ of MSN Autos seems to argue that pairs should always be replaced together:
http://autos.msn.com/advice/article.aspx?contentid=4020124&src=GBT

Snickers
05-05-2005, 01:57 PM
Good Goodyear Eagles (at least those on 1985 Corvettes) will go 18 years without being replaced, although with very little actual use. And it's probably not recommended.

True story! We bought my Corvette in the middle 90s - it'd been parked, mostly, and had low miles. Since then, again, it's been parked mostly, seeing actual driving only during summers. I had the tires replaced last year, and the tech who replaced them asked whether they were the originals. I told him that I thought they were, and he replied, "Yeah. Those were pretty dangerous, actually." Advice that I took to heart.

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