Tire question

[boosted475]

Okay at the risk of sounding stupid, I ask this question.
I recently heard that tires actually have an expiration date?
That after X-amount of years even if the tread is good, the rubber is bad?
Can anyone clarify this for me please?

Thanks.

[Growser]

Recent news reports about old tires failing has experts asking if tires should have expiration dates the same as many other products. Why? Because old tires are failing and killing people!

In a letter released September 22, 2003, a private safety group called Strategic Safety asked the National Highway Traffic & Safety Admin. (NHTSA) to investigate the problem of tire aging. The group says they have documented at least 20 accidents caused by old tires blowing out, 10 of which resulted in fatalities. Most of the lawsuits involving these tread separation accidents have been on tires that were six or more years old.

The group says the NHTSA should have a new rule requiring tire manufacturers to put expiration dates on all new tires.


REPLACE OLD TIRES
Strategic Safety says based on their findings, motorists should replace tires that are more than ten (10) years old, including ther spare tire.

(Note: In Europe, vehicle manufacturers typically recommend replacing tires that are more than six (6) years old.)

The group also says tire retailers should NOT sell tires that have been in storage for more than six years since the date of manufacture.

Tires deteriorate over time, even if they are not used or driven on. The tires may appear to be in like-new condition on the outside, but inside the rubber is slowly deteriorating. This may dangerously weaken the tire and increase the risk of a blowout at high speed or during hot weather.

In one such incident, the owner of a 1964 Sunbeam Tiger was returning from an antique car show. The tires only had 4,000 miles on them and looked good as new on the outside, but the tires were 11 years old. On the way home, one of the tires blew out causing the car to crash. The passenger suffered permanent brain injuries as a result of the accident.
NO TIRE EXPIRATION DATES

The Rubber Manufacturers Association, to which tire manufacturers belong, has responded by saying tire expiration dates may be hard to determine because there are so many variables that affect tire aging. "It's not so simple to just slap a date on it," said Dan Zielinski, a spokesman for the Rubber Manufacturers Association.

Zielinski said a discussion of expiration dates would be worthwhile, but said NHTSA should not act without collecting some solid scientific evidence. Zielinski said tire manufacturers worry that consumers wouldn't pay any attention to the an expiration warning anyway and would not replace old tires with new ones. "People might think, 'Here's the tire industry trying to get us to buy more tires by stamping a date on them,'" he said.

NHTSA issued new tire performance standards in June 2003 but put off an aging test because experts couldn't agree on how to conduct such a test. NHTSA spokesman Rae Tyson said the agency hopes to have a new proposal on tire aging at some point in the future.

Tire makers say expiration dates would complicate their distribution systems because new tires often sit on shelves for two years or more. They also say tires vary in chemical makeup, so one expiration date would not fit all tires. The National Highway Traffic Safety Administration says additional research is needed to come up with an appropriate aging test for tires.

DETERMINING TIRE DATE CODES

How old are the tires on your vehicle? The date of manufacture is indicated by the last group of digits in the DOT manufacture code on the sidewall of the tire. The number is often stamped in a recessed rectangle. The DOT code tells who manufactured the tire, where it was made and when. The last group of digits in the code is the date code that tells when the tire was made.

Before 2000, the date code had three digits. Since 2000, it has had four. The first two digits are the week of the year (01 = the first week of January). The third digit (for tires made before 2000) is the year (1 = 1991). For most tires made after 2000, the third and fourth digits are the year (04 = 2004).

In the photo above, the date code is 8PY806. The 8PY is a manufacturing shift code, and the date the tire was actually made was 0806, which is the 8th week (08)in the year 2006 (06).

The date of manufacture is essential information for car owners and tire buyers because tires deteriorate even if they are not used. European automobile manufacturers recommend replacing ANY tire that is more than six (6) years old, including the spare tire. No such recommendations have yet been made by domestic vehicle manufacturers.

Original source at http://www.aa1car.com/library/tire_expire.htm

[1994Saturn]

I think It is something like 8-10 years,. Even if you dont use the tire they still will deteriorate.

[boosted475]

scary stuff.. i'm going to check every car/tire I buy from now on!

[Astra La Vista!]

I used to sell tires (among other things like mechanical services) and there is some truth to this. I'm not sure how much is marketing hype vs actual factual data, but the oils in rubber do evaporate over time, making the rubber harder as it ages. Hard rubber doesn't grip as well as softer rubber does, so there's the "loss in traction" arguement. Harder rubber is also less flexible, meaning that it tends to crack rather than flex when driven on. If you examine the sidewall of an old tire you will almost certainly detect small cracks.

To tell when your tires were manufacturered: http://www.tirerack.com/tires/tirete....jsp?techid=11 (FWIW, the DOT number is only stamped on one of the sidewalls, so if you can't see it on the outer sidewall, you're gonna have to crawl underneath to peek at the inner one)

From the date of manufacture, exactly how the tires were stored can also result in deterioration. UV, ozone, and pollution can all have an effect on tires if stored outside on racks.

[Jaseball]

Sure, but then make re-treads for semi's illegal as well. It's far more likely for a re-tread to blow out and risk other vehicles as it blows to the remains of the tire sitting on the road for other motorists to run over than it is for a passenger tire blowing out from 'old age.'

[boosted475]

Originally Posted by Jaseball

Sure, but then make re-treads for semi's illegal as well. It's far more likely for a re-tread to blow out and risk other vehicles as it blows to the remains of the tire sitting on the road for other motorists to run over than it is for a passenger tire blowing out from 'old age.'

did I miss something? did someone mention making old tires illegal up there?

[Astra La Vista!]

Originally Posted by Jaseball

Sure, but then make re-treads for semi's illegal as well. It's far more likely for a re-tread to blow out and risk other vehicles as it blows to the remains of the tire sitting on the road for other motorists to run over than it is for a passenger tire blowing out from 'old age.'

Um, no.

First, retreads (for medium and heavy trucks) are not illegal in most places when manufactured within DOT specs. Second, how do you know a tire was a retread simply by looking at the remains? Third, try proving that it was the retreading process that caused a tire to separate and "blow out" on the road (especially since non-retreads blow out all the time).

Retreads are manufactured by vulcanizing new rubber overtop a machine-inspected casing, using both heat and pressure to ensure a perfect bond. State-of-the-art technology is used both during the examination of the potential casing and the actual vulcanization process. Casings can be reused usually up to two times before being taken permanently out of service (A- and B- casings), and this info is included on the retread brand stamped onto the side of the tire.

If a tire on a semi blows out, it is because it more than likely picked up a nail, ran flat, and disintegrated due to the rapid build up of heat. Retread or not, the number one cause of tire separation is heat.

If you want to see the type of abuse retreaded tires can actually take and not blow out, do a YouTube search for Bandag Bullet. 8 tons, 24 litres (two Detroit diesels joined at the crank), two superchargers, four turbochargers, nitrous oxide, 2800 HP, 5600 lb-ft of torque. On retreads.

[mjoekingz28]

keeping an armor-all type protectant should be beneficial to tires

[boosted475]

Originally Posted by Astra La Vista!

Um, no.

First, retreads (for medium and heavy trucks) are not illegal in most places when manufactured within DOT specs. Second, how do you know a tire was a retread simply by looking at the remains? Third, try proving that it was the retreading process that caused a tire to separate and "blow out" on the road (especially since non-retreads blow out all the time).

Retreads are manufactured by vulcanizing new rubber overtop a machine-inspected casing, using both heat and pressure to ensure a perfect bond. State-of-the-art technology is used both during the examination of the potential casing and the actual vulcanization process. Casings can be reused usually up to two times before being taken permanently out of service (A- and B- casings), and this info is included on the retread brand stamped onto the side of the tire.

If a tire on a semi blows out, it is because it more than likely picked up a nail, ran flat, and disintegrated due to the rapid build up of heat. Retread or not, the number one cause of tire separation is heat.

If you want to see the type of abuse retreaded tires can actually take and not blow out, do a YouTube search for]. 8 tons, 24 litres (two Detroit diesels joined at the crank), two superchargers, four turbochargers, nitrous oxide, 2800 HP, 5600 lb-ft of torque. On retreads.

holy crap that thing is crazy hahaha