|The MGA With An Attitude
TIRE LIFE, Time and Mileage Limits - TI-106
This article was triggered by a note on a MGA bbs of the MG Enthusiasts server in the UK, where someone in the know finally told the truth about the tire age issue. For some years now tales abound telling you that you that tires will age rapidly from new (which is true to some extent), and that you should replace tires that are perhaps six years old regardless of mileage or appearance. More ominous is the idea the tires may actually "expire" at ten years of age, and some tire shops will blatantly refuse to rotate or repair or reinstall any tire that is ten years old. If pressed for a reason, they may tell you it is a liability issue, where they might be sued in case of a tire related accident. Bottom line to all that rambling is that there is no legal limit for tire age or usage, except for the tread wear limit when the tire is legally used up when worn down to the wear bars with 1/16 inch of remaining tread depth. Apparently the real reason for the dire warnings is because the tire industry as a whole would dearly like to sell more tires, and they may do that if they can get you to throw away tires that are still useful.
So now the question is, how do you determine for yourself when your tires need to retired (without relying too much on heavily biased advice of tire industry people). There are some obvious tire conditions on both sides of a large gray area. Most obvious, if your tires are worn down to the wear bars, it is time for a change regardless of age (even if they were only two years old). If tires have any significant structural aberration, like a cut in the sidewall or bulge on the tread, it's time for change. On the other side of the wide gray line, if your tires have age cracks in the sidewalls or at the base of the tread grooves, it's time for change, also regardless of age (although they will most likely be at least several years old by the time this happens). Tire aging (other than tread wear) can vary considerably depending on environmental conditions. While it is possible for some tires to be literally dying of old age in 6 or 7 years, it is also possible for tires ten years old (or more) to be in good serviceable condition. This is that wide gray area subject to constant consideration or outright argument.
The following comments came from Neil Purves at Bridgestone/Firestone, who currently holds the following positions:
* Snr. Mgr. Consumer Field Engineering at Bridgestone
* S.Manager Consumer Engineering at Bridgestone Europe NVSA
* Snr Mgr Consumer FE at Bridgestone/Firestone
* Senior Engineering Manager at Bridgestone Europe
More information about Neil Purves can be found under his personal profile on www.linkedin.com
On 29 November 2010, Neil Purves, Belgium, wrote (on the MGA bbs):
Firestone F560 is on the "discontinued" list and a last batch may be produced before they are finally dropped from our line-up. I have kept them in for a number of years but we can not really justify keeping them longer for the increasingly small number of tyres that we must produced. Get them while you can as then they will be gone. I put new ones on this year so I should be okay until 2020 (unless I up my mileage).
Tyre age - 10 years is a reasonable age for a tyre to be replaced. It depends on storage as well as usage conditions. If you store in a cool, dry and above all dark area (most garages?) then they may last longer. If kept outside in one place for some period they may need replacing sooner. If in doubt ask a tyre dealer. If you see cracking on the sidewall or tread grooves then do it soon?
[Please refer: www.tyresafety.eu]
Neil - Bridgestone (owners of Firestone Brand)
I (Barney) can tell you it is hard to compare new tires against old tires, or trying to recall what the prior set was like when new. There is a HUGE difference in grip (a significant reduction of grip) as tires get older. This didn't bother me much when I was buying new tires every 3 or 4 years. Now I drive a little less, so it was a six year span this time, and the difference was much more noticeable. When the tires are new they grip like glue and hardly squeak at all. With several years of age and use they give up some grip and squeal noticeably in hard cornering, as well as losing traction in snow or rain. This sneaks up on you over time, so you may not notice it much as you become gradually acclimated to the deterioration. Installing a new set of tires brings this point home immediately. I have never held onto tires long enough to see cracking in the rubber, but in many cases this difference in grip should be sufficient to merit replacement long before the tires become structurally flawed.