joehonee

Lets cut to the chase....I don't drive my car enough. Hand up, no excuses, its me not the car. That was liberating and hopefully prevents the bombardment of shamers from preaching about something I am already well aware of.

Anyway...despite having more than 50% tread left I have been monitoring the age of the tires on my car (03 X50 Aero 24K) for a while. They hit the 7 year mark so I figured I would follow the Porsche suggestion and get a new set. Before making the appointment at the dealership I inquired as to whether they might have a stale inventory and was assured that their "supplier" rotates them constantly and that is why they bring them in only as needed. After double checking the pricing I thought it made sense to have the dealer do the work. It was a tick higher than others but I needed a state inspection and like the paper trail of service there. Dropped the car off last night and got a nice loaner for the day.

When I arrived today to pick it up I checked the dates and found that the very expensive rear tires (Michelin Pilot Sport) were manufactured in the 7th week of 2017. I discussed it with the service writer, who was the same person who assured me about the fresh inventory, and he said it was out of their control. That didn't suffice so we ran it up the flagpole. Basically their manager offered to give me a $200 discount to which I pointed out that it was not a money thing. I was a bit pressed for time but before I left I recommended that they contact their supplier and find out what control they might have in getting a newer tire in and that we would wait to make the final decision on how to rectify the situation until then.

I was curious whether others have experienced anything similar. The Porsche brand is prolific as to its opinion on tire age for safety reasons. Its hard to understand then how their dealer would mount tires that are more than 1/3 of the way through their life cycle. I understand that my usage of the car is far less than normal resulting in the age of the tire becoming a factor before normal tread wear. I can't understand though that considering how much emphasis is put on the age of the rubber, that anyone would accept 27 month old tires as new.

Thanks

Dock

No judgement from me. It's your car, so drive it as much or as little as you want.

Kevin

Call Discount Tire or TireRack and see what the date codes are on there inventory.. You should be able to find 2019 date codes.

Road King

You definitely made the right call by not buying those tires! Given your car is not a daily driver, why on earth would you want to start out with 2 year old tires?

I concur with Kevin, ask TireRack about 2019 date coded PS2s.

joehonee

Well I sort of did buy them. Despite being told they have fresh sets I didn’t find out until they were mounted and installed. My car was in the service area prepped for pickup. I also already paid in full.

We we have an agreement to come up with a solution. Just trying to figure out what my expectations should be for “new” tire age.

Dock

So does anyone know of independent scientific research (not by the tire manufacturers) that has been done regarding the safety of aging tires? Just what is the rate of physical breakdown of a new tire in storage? What about new tires installed on a car that is only driven 3-4000 miles/year and otherwise sits in a garage that has a 40-70 degree yearly temperature range? What are the safety implications based on the findings? A tire just doesn't go from good to bad (safe to unsafe) at a specific date since manufacture. At what age is the tire unsafe to take to 180 mph? How was this answer calculated? Since my guess is that the majority of street-only 996 Turbos here in the U.S. don't get driven at 180 mph on a regular basis (ever?), at what age is the tire unsafe to drive 120 mph? How about 100 mph? What are the calculations and science that produced these answers (if the answers are out there)?

s65e90

https://www.thoughtco.com/the-scienc...-aging-3234377

T Kono

Carlo_Carrera

There are so many variables exact answers to all those questions is impossible. It comes down to probabilities.

Dock

That NHTSA report they used for some of their information (link embedded in the article) covered a period from 1994-2004, and the results were based on pretty high temperatures (55-70C). What about tires exposed to cooler temperatures? I assume tire manufacturers have improved the compounds since then.

Additionally, research has shown that tires rated for high speed (as are on our 996 Turbos) age slower than non-high speed tires.

What does the current science say?

s65e90

read the link

Dock

That's my point. So coming up with a specific "don't use after" date (six years?) is not an exact science.

s65e90

You have the world at your fingertips. One key point/takeaway is degradation from inside out so basing replacement on a year based service life is a conservative cost of doing business for peace of mind/safety. There is of course also tires that will wear sooner and be more apparent (i.e. Florida where the heat literally destroys everything).

s65e90

My truck tires tend to dry rot in the tread blocks before they wear enough to warrant replacement.

s65e90

The latest report was from 2007 and submitted via various insurance company claim info.