SMI-FST

Did any one see the article in the WSJ yesterday on tire aging while in storage? I said tires over 6 years old that have been in storage are not safe. I have a 65 that has radials on it that are 20 years old but probably have less than 5,000 miles on them. Am I at risk when I drive this car? What does every one else do/think? I know I should just drive it more to rack up the miles and wear out the tires.

Rons65

I would tend to not trust the tires at that age - unsure of PA climate, but in Arizona, the last thing you want to do is drive on old tires no matter how much tread - too much heat! If you have them for show or NCRS, ok to roll around on, but as a driver I would replace - just my 2 cents!! :flag

SWCDuke

Didn't see the WSJ, but heard on the radio yesterday that DOT decided NOT to require manufacturers to mold an "expiration date" into new tires. The problem is that there are simply too many variables involved to establish arbirary rules.

Tire aging has a lot to do with rubber compounding - most compounds are blended with "anti-aging" chemicals, and then there are the big environmental issues - temperature, UV light, and ozone.

One visible sign of aging is small surface cracks in the sidewalls, but these do not necessarily mean a tire is unsafe. The internal bonds in a tire can weaken with age, but there's no way to inspect their intregrity.

Bottom line is that old tires are not necessarily unsafe, especially if you know they have not seen much UV or ozone exposure and have not been subjected to high heat for extended periods (like summer in Arizona), but frequent visual inspections for surface conditions and abnormalities due to internal bond failures is prudent.

Duke

Tom Piper

I've personally had bad experience with old tires.

I examined some tires on a vehicle I bought very closely and could see nothing wrong with them. I knew the car had been idle for awhile, but liked the low mileage. On a trip, one of them blew out -- then, you could see the cords had deteriorated severly -- dry rot.

I will never trust old tires again.

Tom Piper

SWCDuke

What was the make, model, and speed rating?

Higher speed rated tires are inherently stronger and built to better quality standards including QC inspections. Personally, I would rather have a set of ten year old V-rated tires on my car that I know were stored properly and not subject to poor environmental conditions than a new set of non or low speed rated 205/75R-15s that are so common, or, in particular, a set of repro bias plys.

Virtually all tires rated "H" or above have one or more spiral wound nylon cap belts that will keep the tire together if there is an internal separation. I've experinence several separations while hot lapping race tracks, but in every case the nylon belt kept the tire in one piece and they held their air. The failure was noticeable due to vibration and visual inspection showed a bulge in the tread area.

In one case I even drove home the 75 miles from Riverside with no problem other than the vibration.

If ALL tires had such nylon cap belts the Ford Explorer tread separation fiasco and several hundred blamed fatalities would have never happened!

Duke

66427-450

i had a right front tire come apart "at speed" about a year ago, almost took the front fender off............. tires were ~ 15 years old, but had 95% tread, and looked like new. The steel belt came off and ended up wraped around the spindle area, after busting the fender loose, tearing off the blinker corner of the fender, tearing up the front of the side pipe cover, etc. it took months to get the body back 100% to my satisfaction.

it could have been a defective tire/freak thing, it was a "premium, name brand" radial.

so...... no more old tires for me :-), no matter how good they look.

:seeya


[Modified by 66427-450, 3:09 PM 9/23/2003]

JPatrick

From reading the WSJ article it is pretty clear that there is an aging issue. It has been recognized by the Britts and the German auto makers who recommend tossing tires after 10 years or 6 years if not used. The U.S. tire makers say they are studying the issue and so far have found it very difficult to come up with a "one size fits all" expiration date.
Of course in the U.S. you must figure how the lawyers fit in. The group making the fuss for expiration dates also works for lawyers. There is a mention of a guy who rolled his classic Sunbeam (the Tiger not the Toaster) and blamed his 11 year old tires with 4000 miles. His girlfriend was badly injured and he is suing.
As for me--the older my tires get the slower I go. Even then I worry about ripping to pieces a fender if the tread separates.

And won't it be great when they start putting expiration dates in 5 different languages on the sidewalls. Should make a great looking raised white letter. :cool:

SMI-FST

SWDuke makes a good point about speed rated (H or higher) staying together as this is the type of sudden failure the article talks about. My 20 year old tires are not rated and I think a new set is in order next spring.

simard

It was a 12 year old Riken (Michelin) tire. H speed rating. Tire did not go flat, just lost 1/3 of the tread. Wow is that noisy.

Tom Piper

The tires were on a luxobarge (TownCar). They were steel belted radials -- I think one ply was nylon the other rayon. I have no idea of the speed rating -- that was ten years ago.
After that tire went, I did some reading on tires. The one thing that I remember was the so called experts said that you can't tell a dry rotted tire by looking at it. Since I pulled these tires off the car, inspected them, and found nothing suspicious, I believe it.

Tom Piper

SWCDuke

It pays to get smart on tires. Guys agonize over sidewall styling, but pay virtually no attention to a tire's performance characteristics. Today's DOT tire requirements are totally inadequate for today's driving conditions. They are over 30 years old, but it remains to be seen if new regs will actually address the performance and safety issues, or just be more political BS and junk science.
One reason why I wrote the long and extensive article for The Corvette Restorer was to helps guys get smart on tires, and the basic information there on how to determine a tire's performance characteristics and safety margin apply to ANY vehicle.

1. Never buy less than a H-rated tire for ANY vehicle you own. In the case of a vintage Corvette, a SUV, truck, minivan, or small to mid size sedan this may require some research and selecting a non-OE tire size. You life could depend on it.

2. Pay attention to the UTQG rating. The first letter should never be less than "A", which is a comparative reprsentation of the tires wet braking performance. The second letter should also never be less than "A", which is a comparative representation on how well the tire can resist heat buildup. As a rule a tire rated "H" or above will rate an "A". Less than a H-rating is usually B or C. If such marginal tires are run at high speed in hot weather on a highly loaded vehicle with typical OE recommended or lower tire pressure you are looking for big trouble.

3. Look for a LOW, yes LOW treadwear rating. Tires that are rated at 600 with 80K miles tread life expentancy are hard as rocks and get worse with age. A lower wear rating will be a softer compound that will achieve higher grip for better handling and breaking. I can get about 30K miles from a set of tires rated at 200 on my cars. For my toys that I don't drive often I like DOT legal racing tires rated at less than 100, but, unfortunately they are not available in sizes that will fit Corvettes with 15" wheels.

Duke




[Modified by SWCDuke, 7:06 PM 9/23/2003]

LT1driver

evening news last night talked about same thing. Personally, I wouldn't drive at speed if I had tires older than 5 years old and only in town. A blowout can and most likely will cause damage to body and the like, is it really worth it in your time, money not to mention your life :confused: