mark kibort

36psi is plently . especially, since most tires are designed to run at 36psi hot.

who knows about what caused the failure. looks like much of the evidence was caused when the tire went flat. that happens in a few revolutions of a flat.

6 year old tires are no issues. I raced with 04 toyos with no issues at all. they looked like brand new right to the cords. If a tire has issues, it will show signs of age internal or external.

pcar928fan

Bruce,

Sorry to see that! SUCK DUDE!

Tails,

The S4's rear pressure per factory specs is 44, on GTS's that number is 36... 36 is correct for a GTS wheel RDK sensor.

inactiveuser1

Usually where the DOT number are the last 4 digits at the end are the manufacture date.
Example:
DOT XXXX XXXX....4702
47 would be the 47th week of 2002.

Another Example:
DOT XXXX XXXX....0907
09 would be the 9th week of 2007.

GeorgeK

What model Michelin is that tire?
Seems weird to have a 2nd tier Michelin with M+S rating on a GTS...

NoVector

They're Michelin Plus Sport A/S and DOT ends with: 4M 6WFYRX 1106. So, I guess these were made in November 2006 (?) Although I don't have a receipt from the PO showing them purchased in the past 4 years, it would make sense--these just didn't look that old and I honestly didn't give them a second thought during the PPI last year--they looked great. I am going to send an e-mail w/ pics to Michelin just to see what they say, but I imagine it's going to be "suck it up, buttercup; you're not the original purchaser and shift happens." But if you see someone selling one Michelin Plus Sport tire on e-bay, you'll know what happened

Thanks again everyone / Bruce

Mrmerlin

they were made the 11th week of 2006

FredR

Bruce,

Not sure what your temperature profile is like in your neck of the woods but I guess it is pretty hot during summer and not too far from what we see over here- maybe you regularly see temps up to 40C? I know in Arizona they get those sort of temps. Tires degrade relatively rapidly with hot tarmac temperatures. Over here tires are OK grip wise for 2 years and structurally dodgy after about 3 years depending in make. Michelin's have tremendous grip but they do not have the longest life expectancy in terms of ability to withstand the heat. Combine this potential degradation with perhaps some under pressure event or have a flat/blow out and that tyre will be totally trashed within 100m I'll bet. For summer time you should be on PS2's [fantastic tires] but they are not recommended for cold winters.

As someone stated earlier, if the tires have stood for some time that does them no good either. The rubber needs to be worked to keep it supple.

Above all else, the tyres must be in A1 condition. A little trick I was taught by a Michelin factory chap was to try pulling those hair like casting tails on the tire wall. If they are pliable the tire should be OK- if they are brittle throw the thing away.

Even in the [relatively cold] UK I have seen tires fail with age. they simply do not last forever and even though they may look OK it does mean to say they are.

Difficult when they appear to have so much tread left but you are talking about your life here. Before thinking about opening up any performance car I would want know that the tires are in perfect condition. All it takes is one curbing by the PO to damage the inside of the tire. thatis why if I buy a second hand car of any type, the first thing I do is change the tires unless I know and would trust the PO with my life.

Regards

Fred R

bigmac

When you think of the costs of a new set of tires V/S the costs and value of You, Get a new set all around
and drive securely for the next 3-5 years.

Ispeed

You should run summer performance tires, living in TX. Not M+S mud and snow all seasons.

VehiGAZ

Not at any speed. Mark Kibort (who posts what he learns from his own personal experience) notwithstanding, most others, including those in the tire industry, will tell you that 6 years is the MAX for most tires, and you should not drive on them at all. Consider your own blowout... although we've sorted out that it was probably not caused by age, it happened at a relatively tame 40 mph. Would you want to take the chance of going through that again just to squeeze that seventh year out of a set of tires?

Next tires for my shark will be the stickiest 12,000-mile suckers I can find - I will get to the age limit before I wear them out.

Erik N

No way. I run the same size rears, and 36psi is PLENTY of air! I don't care how spirited your driving is- even on a rough track, 36 is usually too much.

Plus the tread shoulders look untouched from asphalt. That tire wasn't driven hard, underinflated.

I bet Porsche specified 43 psi for fuel economy... not for performance.

VehiGAZ

Different tires need different pressures. The suggested tire pressures are valid only for the OEM-spec tires for your car. The engineers set the pressure spec based on the ride/handling/wear balance they are shooting for based on the OEM tires.

If you change your tires from OEM-spec - and most of us have at this point (are true OEM-spec tires even available anymore??) - then the factory spec becomes almost meaningless. If you fast-forward 20 - 30 years in tire compound and construction development, the OEM pressure spec becomes meaningless. If you upsize your wheels, the OEM pressure spec becomes meaningless.

James Bailey

Due to the agressive tread patterns popular today MOST high performance tires ALSO have a mud and snow rating. There are not really "snow tires" they just look like them . Also it is very likely that your RDK has been jumpered to be none functional. And yes tire rubber breaks down with age but is most intolerant of running with low pressure. I towed the kids 21 ft Scarab to Lubbock Tx blew two tires along the way 5 year old trailer specials BUT the prior owner never read the sidewall which called for 65 lbs max....he ran them low at car pressure but only for short hauls to the marina. So not too surprising when they let go at 70 mph in Arizona one after the other about 100 miles apart. We had extra spares so just a slight delay.

mark kibort

again, so many factors. I would trust my life in MY 6 year old tires, because I know what they have been subject too. a guy that garages his car, vs one that keeps it on the street, vs a car that sits in the sun, vs living in arizona, vs seattle, etc etc........ you get the idea. my buddies '96 trailer tires are so cracked it looks like they should be leaking (original tires) vs my 95 tahoe tire spares look fine, but I wouldnt trust them other than spares to get to the shop and back for the truck.
my toyo RA1s are kept in the garage, and the tires I race with, would be on the car, and in the garage. in the end, they only see sun and pavement for 4,000miles a year, so its a little different. so I do agree, if a normal guy is driving a car, that sits in the sun a lot, and has 6 years on them, absolutely, toss them! thats got to be near 60,000 max.

tires are strong if used correctly, and they age well, but are VERY unforgiving for the slightest miss use. (i.e too low pressure, etc)

-m

Ispeed

OT: my life improved when I put MK on the ignore list.

Check your tire pressure...