1985 300D: Keep or replace 5.5 yr. old tires with low mileage?

[dogguy]

My 1985 300D has a set of 4 Yokohama P195/70R-14 Avid Touring-S SL tires.
They were installed 5.5 years ago and have only 3,300 miles on them - I only drive the car about once a month and rarely on the freeway. The car is garaged. The tires lose about 2-3 psi every 6 months or so.

I plan to replace the rims this year (returning to originals) and am wondering whether it would be best for me to:
A. Simply dismount and remount the tires onto the new rims.
or
B. Replace the tires given their 5.5 year age.

Stated another way: Despite the quite low mileage on the tires, is 5.5 years such that they are physically degraded enough (even though tire pressures remain good) to call for replacement?

I would appreciate any advice on this (wasn't successful in finding much specifically in the archives on this subject).
Thank you.

[Sugar Bear]

I would be willing to drive on them but not pay to mount and balance them on new rims because they will be due for replacement in 1-2 years and the sealing bead may tear due to age during the dismount/mount operation.

[dogguy]

Originally Posted by Sugar Bear

I would be willing to drive on them but not pay to mount and balance them on new rims because they will be due for replacement in 1-2 years and the sealing bead may tear due to age during the dismount/mount operation.

This is quite helpful! As always, thank you.

[shadetreemechan]

I think you should dismount them and give them to me!
No seriously, if they are not visibly cracked there is no issue in using them. I have had beads tear when mounting 20 year old tires, but even then rarely. If they look good I would (and frequently do) run them well past 10 years. The michelins on my 240 right now are 14 years old. I bought a parts car that had been parked when they had less than 5K on them. I am going to run them till they are bald.

[dogguy]

Originally Posted by shadetreemechan

I think you should dismount them and give them to me!

Heh, heh
They are nice tires those Yokohamas. They've served me well.

Originally Posted by shadetreemechan

if they are not visibly cracked there is no issue in using them.

A few months ago before I applied 303 after washing the car, they looked quite good. Tomorrow I will do a close inspection with a bright light but I still think they are in quite good shape.

Originally Posted by shadetreemechan

I have had beads tear when mounting 20 year old tires, but even then rarely. If they look good I would (and frequently do) run them well past 10 years. The michelins on my 240 right now are 14 years old.

That's great. And impressive.

Thank you for sharing your experiences. This is helpful to me.

[shadetreemechan]

Full disclosure, I am running those Michelins on my car after taking them off my 17 year old daughters 300D. At that age, they are cracked and rotted, but still roll true. I figure if they go I would rather them blow on my car than hers.

[dogguy]

Originally Posted by shadetreemechan

Full disclosure, I am running those Michelins on my car after taking them off my 17 year old daughters 300D. At that age, they are cracked and rotted, but still roll true. I figure if they go I would rather them blow on my car than hers.

I appreciate your full clarification. It reminds me of something that I am currently taking into account and that compelled me to start this thread:

In 2019, I had a set of 4 Yokohama P195/70R-14 Avid Touring tires on the car. They were 6 years old at that time and had 28,000 miles (not a lot to my way of thinking) on them.

I was driving 60 MPH on an interstate, dry road and clear weather, had only been driving for 15-20 minutes, no loud noises, and suddenly the back right tire blew out.
A light load, too: The only things in the trunk were the spare tire, an emergency kit, and a bag of tools...and no passengers either.
The tire shop attributed the failure to age and found nothing that would indicate otherwise. Not a rigorous scientific analysis, but there I was. So, in short, I'm a bit weary of driving my car on tires 5+ years old - just my opinion.

[Sugar Bear]

IIRC, I've read that the tire industry standard for replacement is no more than 7 years of use and never more than 10 years from the date of manufacture. Don't know if it is true or not. Some high performance car manufacturers recommend a 5 year max.

[dogguy]

I did a modest internet search before starting this thread and the general age range that I came upon numerous times was 5-7 years. Seems that most if not all of the degradation is based upon a whole variety of chemical changes in the tire materials brought about by such things as ultraviolet light, temperatures and their changes, weight on the tires...on and on.

[Graham]

The 5-7 year numbers no doubt come from tire manufacturers who like to sell more tires! In a way, they can be right if the car is a daily driver that might see 12,000 miles a year and tires are exposed to sun and other conditions.

My 1985 300D gets driven about 1500 miles/yr. Usually quite sedately! The tires have about 75000 mile tread life. Should last for 50 years before they wear out. But, as we know, rubber degrades over time. The numbers I read are more like 6-10yrs with the latter number probably OK for low mileage cars stored indoors.

A lot depends on how the car is driven. My car seldom gets to as high as 60mph, most of time much less. I won't change the tires until they are about 10yrs old or even a bit higher if they are otherwise still good.

BTW, my original rims don't leak. The MB alloys on my later model E320 did and I had to replace the rims.

[g300d]

I've done most all the possible options, from replacing at the 5-year mark or so to roll em till they blow lol!

Nowadays I rely less on time and more on actual condition like signs of degradation like dry rot. Higher tolerance allowed for the city driver cars than the ones that run on the freeway.

I found the timeframe pretty variable. Garage kept car tires last a lot longer.

[dogguy]

Originally Posted by g300d

I've done most all the possible options, from replacing at the 5-year mark or so to roll em till they blow lol!

Nowadays I rely less on time and more on actual condition like signs of degradation like dry rot. Higher tolerance allowed for the city driver cars than the ones that run on the freeway.

I found the timeframe pretty variable. Garage kept car tires last a lot longer.

Helpful, thanks-

[Shern]

I think if there’s any doubt, you should probably replace them.
It’s relatively cheap insurance.

[dogguy]

Originally Posted by Shern

I think if there’s any doubt, you should probably replace them.
It’s relatively cheap insurance.

Yes, good advice I think. I have experienced two blowouts in my life when I was driving...one country highway (parents car back in the day) and one interstate with my 300D...no fun at all and *especially* harrowing on the interstate. Cheap insurance yes and some peace of mind, too.
Thank you.

[t walgamuth]

I had one blowout in my 72 220d. it apparently had a nail in it which leaked down until it blew. I misunderstood the swaying of the rear to be from wind.

I have had at least two on a trailer using older tires. A blowout will do a lot of damage to a travel trailer. I generally now replace any tire with less than half tread

When on the road I feel my tires at every stop for heat. If they feel significantly hotter than the others I will correct tire pressure and do repair as needed.