Tire manufacture dates and safety
 

Just saw a report on network news about companies selling people tires manufactured a number of years before as new. One guy bought 4 year old tires as new and put them on his son's car. He drove on those tires for 5 years and they were effectively 9 years old. A tire blew out on a freeway and the young driver died in the resulting rollover.

So I went out to the garage to check out the tires on my cars... and discovered the new tires on the BMW (my DD) purchased this calendar year were a year old when sold to me through tirerack.com. I'm ok with that because I will wear the tread off in two or three year's time easily enough.

However, the Kumhos on the Boxster's track rims have a manufacturing date of 40th week of 2005, yet they only have less than 4000 miles on them and look almost new. I usually don't drive well enough in the twisty bits to get up to 110 mph or more on the straightaway the way the more experienced drivers do.

Am I safe for the high speed DE next month?

i think really old tires start to show cracks on the side walls and between the tread

Imho
 

When I bought new tires for the Box last year I got really concerned about manufacture dates. I spoke to the owner of the local tire store about older tires and he told me if they don't show signs of age (cracking, drying, separation) then you don't need to worry about them.

Anything beyond five years is suspect, as the rubber starts to dry rot and breakdown forming small cracks...worse thing happens is tread separation when put under stress. I'd inspect my tires thoroughly for any signs of cracking; is it worth the risk of damage to your car or injury due to old tires? I'd say you are borderline, but this is just my experience as a track junkie...I'm not a tire engineer.

Interesting article in Dec Excellence
 

re the space saving spare tires in various P-cars. Many in our Boxsters are 10+ years old...some 25+ for other models. Many aren't made any more. Many not designed for the tire only to be replaced. Some designed not to deteriorate like normal tires with age. Replacements horribly expensive...for a 996 $500 or so but how old are they?

If you ever have to use one, remember they are mileage and speed limited. Every time I get passed at 70 by someone running on one I just try and get out of their way.

How long since you checked your spare's tire pressure and examined its condition?

Recently, I put 1,800 miles on a "brand new" set of tires that were 15 years old. They came on a 15 year old car that had only 124 miles on it. Other than horrendous flat spots from sitting too long, they were pretty ok. I drove them as hard as I've driven any tires. Not the absolute best traction I've experienced, but not the worst either.

I think most of the stories that get blamed on bad tires, are actually caused by under-inflation or bad driving, or both.

Those fifteen year old tires had to be as hard as hockey pucks...talk about lack of grip!

There are some very good technical articles on the net when you Google the subject.

i hope he put them on a drifting car and not on the street.....times must really be bad in cali.

My understanding on the matter is that you don't want tires on your car that are more than 5 years old from the date of manufacture, regardless of mileage. From the factory there's lubricants that are embedded in the rubber to keep it soft, and those seep out over time and due to being exposed to the elements. So even if the tires aren't showing serious dry rot and only have a few thousand miles on them, that doesn't stop them from aging.

It's much like engine oil, really. Just because you only drove the car 1000 miles this year, would you not change the oil because you've still technically got another 9000 to go? I hope not, since the components of the oil will still break down just from sitting over time.

There were tires from 2002, 2003, and I think 2005 on my Boxster when I bought it a few months back. The car had basically sat on the lot where I found it for about 5 years and rarely moved. I actually drove close to a good thousand miles on those things until one day I happened to look at the right front (one of the 2002 tires) in the driveway and saw that the tread was literally separating from the carcass. :eek: I didn't move the car again until I'd made an appointment to get on a new set of tires that were made at the beginning of 2010 at the tire shop less than 2 miles away. I'm sure they'll be long worn out and gone before 2015, the way I drive it. :D But there's no way I'd ever let my tires go longer than that, even if they're still full of tread...to me it's just too much of a dice roll on old tires.