Running on Old Tires vs. New Tires

I had put some 50 year old Michelin XAS on my MGA coupe to move it around while getting it repainted. For some reason ( I forget exactly what) I had to drive the car a few blocks and it was wet out.

Holy Crap!  

Back in the days when I had a really short commute, I still had the original Michelins on my 9 year old Jetta. One day a vibration developed, the cause being a giant bubble forming in one of the tires. Despite looking good on the outside, the rubber was breaking down on the inside. I replaced the others immediately.

is nothing compared to what happened to a fellow Tiger owner. He was at speed on an Interstate when one old but cosmetically good tire catastrophically failed. Car totaled, driver and passenger nearly so. This accident was featured on one of the TV investigation shows (20/20?) a number of years back.

So tire age ruins more than handling.

This is a bit embarrassing and I wouldn't recommend keeping tires on this long. I bought my '91 Miata new in late 1990. In 2003 my dad and I went to Monterey in August to experience the yearly celebration of all things cars. It was the last year that the national Miata club facilitated a package deal for the long weekend of events including staying at the Asolimar state park facility. The Miata was still riding on its original Dunlops at 17,000 miles and likely 13 years on the tires and few autocrosses. The car was always garaged so the tires got very little exposure to the elements, but looking back it was foolish to not have replaced them. Fortunately we had no issues with the tires and I even pushed them to 100 mph on an isolated road in central California on the way home. They had been replaced for the Route 66 trip in 2013 that I took with my son. Thankful for guardian angels!

This should just be another chapter in the "Rubber Handbook".

Looks OK

does not equal

Is OK

RUBBER AGES ALL BY ITSELF in our world.

In reply to David S. Wallens :

I learned my lesson 30 years ago driving to the Hamptons on Montauk Highway.I was accompanied by my four and six year old boys at the time.

I was driving my 1957 Bentley Park Ward Drophead BC78BG.

I was going 70 ..the car was happy.. 

I was going 80.. the car was happy. 

I was having a wonderful time.

People in other cars started to honk and point. I thought it was because of my unique car. I now think that they saw a pending disaster.

All of a sudden, the right rear tire exploded. Even though it had been detailed and look brand-new with great tread the tire must have been 12 years old.

We swerved.. I was sure that the car was going to flip over. I, very luckily controled the car with my two young boys in it. 

Someone was watching over us that day.

Massive sweat pouring off my face, my four-year-old son looked at me and said "Gee  Dad , that was great, let's do it again ! "

Ever since, every car I've owned and driven had great, less than five year old rubber.

I'm happy to say that my 4 year old son didn't get to "do it again." 

Mark Dweck

In reply to Mark Dweck :

In June of 2019, I was driving a friend's 1974 Fiat Spider on highway 30 in Oregon, following the Columbia River from the coast into Portland.

At one point, the car started vibrating almost uncontrollably, the wheel wanting to buck out of my hand. Thankfully, SCCA driving school -- though many years in the past -- left me with the skills and cool head to keep the car on the road till we found a safe place to pull off.

The right front tire had delaminated, though the tread was still mostly attached (which, as Miracle Max might say, is not the same as ALL attached).

I found the spare, which was about the same age as the other tires, as well as all the tire changing gear. I swapped tires at the side of the road and resumed the drive to Portland, cautiously.

Some 50 miles later, I pulled off for an unrelated reason and saw the spare beginning to delaminate.

I called the friend/owner of the Fiat, who showed up a while later with his truck and trailer. 

The punch line? I looked on several of the Pirelli CN36 tires to see what the date code was.

There was no observable date code, which ISTR means they were made before something like 1987, but I'm not clear about that.

Spare on top, delaminated RF below. (Hoping the aspect ratio works out when I click "Post...")