Outer Limits 4x4 Board

I have seen some posts on a couple of other forums stating that it is illegal to use tyres older than 5 years old or somesuch. And that tyres have a "use by" date from the manufacturer of 5 years.

Does anyone know if there is any truth in this. I can't turn up any official documentation stating this, so I suspect it is mostly BS???

BS, we used to knock them back if they had any type of damage or failure due to age but that is all.

mkpatrol wrote:BS, we used to knock them back if they had any type of damage or failure due to age but that is all.

Cheers. I found this:
http://www.zimbio.com/AC+Delco+Auto+Par ... uring+Date

But it just states "reccommendations"

I thought that as long as the tyre is in good serviceable condition (safe), it was legal. 5 years would be a bit much, hey.

From another forum:

As I mentioned earlier, my son was knocked back (Qld RWC) as the tyres were over 5 yo. They were a quality 215/65x15, purchaced new by me about 4 - 4 1/2 years previous and showed no sign of defect. Ben enquired at QT and was told by an inspector that QT deemed any tyre over 5 yo unroadworthy.

ISUZUROVER wrote:From another forum:

V8Ian;1000558 wrote:As I mentioned earlier, my son was knocked back (Qld RWC) as the tyres were over 5 yo. They were a quality 215/65x15, purchaced new by me about 4 - 4 1/2 years previous and showed no sign of defect. Ben enquired at QT and was told by an inspector that QT deemed any tyre over 5 yo unroadworthy.

I'm not doubting what you say, but that means that probably many vintage cars are in that category, as well low kilometer drivers who don't do the ks to wear them out in 5 yrs...

RED60 wrote:

ISUZUROVER wrote:From another forum:

As I mentioned earlier, my son was knocked back (Qld RWC) as the tyres were over 5 yo. They were a quality 215/65x15, purchaced new by me about 4 - 4 1/2 years previous and showed no sign of defect. Ben enquired at QT and was told by an inspector that QT deemed any tyre over 5 yo unroadworthy.

I'm not doubting what you say, but that means that probably many vintage cars are in that category, as well low kilometer drivers who don't do the ks to wear them out in 5 yrs...

I didn't originate the quote above (the ben mentioned is a different Ben). I agree with you. Given the average km most people drive, half the tyres out there must be older than 5 years!

I thought it referred to people selling new tyres that were older than 5 years, sort of remember hearing that a while ago

Mind you it's not unreasonable to suggest a 5 yo tyre is not good. Don't know about some of the newer rubber but many older tyres went hard. We had some Michelins on wifes car years ago, great tread, looked new, no cracking, but no grip. The tread was hard as a rock.

Was old man tails too years ago to sit tyres around for a while to harden them up so they didn't wear out as quick. Only saw this happen at local tyre shop about a year ago. Older guy bought set of Coopers and took them home to sit int eh shed for about 12 months so they would be harder when his current ones needed replacing.

when I was in the tyre stuff, we had a few people that buoght tyres 12 months before they needed them. Also most of our supliers wouldn't do warranty claims on tyres over 7 years old as they classed the safe life as 7 years.

Also how to tell how old a tyre is:

Usually next to the serial number it is a four digit number eg. 3408, the first two digits is the week of the year, in this case the 34th week, and the last two are the year, 08 in this example.

fester2au wrote:Mind you it's not unreasonable to suggest a 5 yo tyre is not good. Don't know about some of the newer rubber but many older tyres went hard. We had some Michelins on wifes car years ago, great tread, looked new, no cracking, but no grip. The tread was hard as a rock.

I agree, the amount of tread doesn't make the tyre safe if it's gone hard.

I nearly learned that the hard way when I got a resto'd jag on the road after it had been sitting for years; the tyres looked good but hooooooly shit.

chimpboy wrote:

fester2au wrote:Mind you it's not unreasonable to suggest a 5 yo tyre is not good. Don't know about some of the newer rubber but many older tyres went hard. We had some Michelins on wifes car years ago, great tread, looked new, no cracking, but no grip. The tread was hard as a rock.

I agree, the amount of tread doesn't make the tyre safe if it's gone hard.

I nearly learned that the hard way when I got a resto'd jag on the road after it had been sitting for years; the tyres looked good but hooooooly shit.

But going hard is an environment issue rather than age.

KiwiBacon wrote:But going hard is an environment issue rather than age.

Is it? I have no idea, I just assumed it was volatile components in the compound very slowly evaporating away. What is the real explanation?

chimpboy wrote:

KiwiBacon wrote:But going hard is an environment issue rather than age.

Is it? I have no idea, I just assumed it was volatile components in the compound very slowly evaporating away. What is the real explanation?

Some atmospheres make it happen really quick. Apparently ground level ozone (found in smog) is great for it.

IMO it's only the outer layer which is a wear surface anyway. If you keep using them it's not a problem. If they take a shine then drive easily until it's scuffed off.

KiwiBacon wrote:

chimpboy wrote:

KiwiBacon wrote:But going hard is an environment issue rather than age.

Is it? I have no idea, I just assumed it was volatile components in the compound very slowly evaporating away. What is the real explanation?

Some atmospheres make it happen really quick. Apparently ground level ozone (found in smog) is great for it.

IMO it's only the outer layer which is a wear surface anyway. If you keep using them it's not a problem. If they take a shine then drive easily until it's scuffed off.

I wish you would post the above on AULRO - where everyone is telling me I am an idiot for driving on +5yo tyres...

But re the physics/chemistry of this happening. It seems to basically be a diffusion process, possibly exacerbated by UV. What part does ozone play exactly? Does some photochemical reaction occur? Any references for this?

ISUZUROVER wrote: But re the physics/chemistry of this happening. It seems to basically be a diffusion process, possibly exacerbated by UV. What part does ozone play exactly? Does some photochemical reaction occur? Any references for this?

I happily drive on much older tyres.

I had a chemistry text book which covered it under "evironmental chemistry". Unfortunately some wanker stole most of my text books that year. Nothing else in my room was taken, just the text books.

Thanks - just found it in my environmental chemistry textbook. But just a short statement that ozone hardens rubber.

Wikipedia even has info on it:

The problem was formerly very common, especially in tires, but is now rarely seen in those products owing to preventative measures.

http://en.wikipedia.org/wiki/Ozone_cracking

So it is more an affliction to older technology, modern rubber should be alright. Also means there's no point aging new tyres.

I can tell you though in the older days it was more than just the surface layer, we could not scrub those Michelins soft again.

Thought UV had lot to do with it cause I also remember the same old blokes saying you should store tyres in black garbage bags to keep them in good nick if stored for long periods.

i ran 15 year old tyres for a while, didnt wear in 10 thousand K, terrible grip and ended up blowing one out.
5 is still a new tyre to me, 10 and i wouldnt use it.
4 or 5 and i wouldnt buy it.

when a tyre goes hard, it goes shiny, and theyre no softer in the centre than they are on the outside sorry to say...

cheers, andy

far as i know tyre year and month it was made are stamped on the tyre
been told not suposed to be older then 3 years

matthewK wrote:far as i know tyre year and month it was made are stamped on the tyre
been told not suposed to be older then 3 years

Yes they are. Well actually week and year. So tyres made in the first week of 2009 would be 0109 Last week of 09 would be 5209.

What do you mean 3 years??? use or sale?

I just did a survey of my tyres yesterday.

Came up with.
01
03
04
05
07

The 01 tyres (worn out BFG AT's) were the hardest of the lot, but because they were BFG's rather than their age.
Aside from the 07's (bought last year), there was no appreciable difference in hardness or cracking between them.

I'm not worried about it.