Older tires--lightly used--replace anyway?
 

Should I replace tires based on tire age alone? Replacing tires every 6 years regardless of wear seems to be a not uncommon recommendation. I have about 6000 miles on my 7 year old Continental Extreme Contact DWS. Excellent tread, no sidewall cracking, no uneven wear, no sign of any damage. Garaged car with very limited harsh weather and UV exposure. I know that tire compounds do deteriorate with time but throwing these "good looking tires" away just seems wasteful.
Regards

Maybe sell/give them to a Used Tire Store?

This can be a pretty contentious issue. Some people really buy into the expiration dates. But two things cause tire rubber to deteriorate rapidly, ultraviolet light and ozone gas. Premium tire manufacturers add anti-oxidants like Santoflex to the rubber compounds that are pretty good at slowing the process. Five or six years is a good recommendation for the "typical" vehicle that's parked outdoors at mid-latitudes. That's about what I've gotten on trailer tires here in Texas. But classic and antique cars that are kept inside well-sealed and dark garages both night and day can have tires like new for decades. Its all about exposure.

There is a limit tho and if you've ever watched "Chasing Classic Cars", I do kind of cringe when Wayne pulls a half million dollar car out of a barn, barely gets it running and immediately takes it out on the highway in front of his shop on the original tires. Of course he won't change them because they're "original", but a half million dollars on the line and tires 50 years old I just couldn't do. However, I spent part of today "exercising" a $20K classic car with 20 year old tires. Just do like people have been doing since tires were invented. Inspect your tires very closely on a regular basis and keep your senses keen. If you start to see some fine micro-cracking starting to form or if you start to notice they sound different or ride different, then its getting to be about time.

There is no law that requires you to replace tires over a certain age. The answer depends on your risk tolerance, based on when, where, and how you'll be driving.

At one extreme is doing local errands on a nice day at speeds below 40mph. At the other extreme is a track day in inclement weather. Those tires are unsafe at the track and should be replaced, but are less risky when running errands.

Outwardly, your tires appear to be in good shape, with plenty of tread, even wear, no dry rot cracks or sidewall bulges, and no leaks. You can blow out a brand new tire by hitting a curb or a pothole, but do you worry about that happening? Don't worry, be happy - so replace those tires and sleep well. Or not. The choice is yours.

I think you're more likely to be the victim of some idiot driving on bald tires who loses control and slams into you.

The tires on my car were 10 to 14 years old. No cracks or leaks but they produced a lot of road noice which I think is due to that rubber hardens with age and produces less grip(nothing I noticed though). I changed mine mostly because of the road noice.:-)
6 years should not be a problem.

@Stuart S , you forgot to add “or those with old tires and no grip” ;-)

i have the same tires. the sidewalls cracked in a couple of spots within the first two years. while garaged every night, that garage is not insulated -- and before covid i never avoided driving the car to work on supremely hot, or cold, or otherwise inclement days, where it would sit in an open, surface parking lot all day.

i have continued to throw the car through turns at whatever speed i feel like (within reason :icon_cool:) and although obviously they will give way sooner or later, the evidence suggests they're not about to explode on you or anything.

You are correct. As tires age, the "stickiness" in the rubber compound dries out and becomes less effective. Although that tire may still have plenty of tread depth left, it now has poor adhesion and is prone to skidding and loss of driver control.

It's like driving on UHP Summer tires during the winter, when temperatures are well below 40°F.

Safety, of course, is a primary consideration. The car is never brought to a track and while the tires are AS, the car is stored for the harsh Winter months. The car is primarily used for local travel but sometimes a highway is involved. Come Spring I will reexamine the "old tires" get a feel for the car's behavior and decide which way to proceed.
Thank you all for your input.
Regards

This article gives a reasonably balanced picture: https://www.edmunds.com/car-maintena...our-tires.html

This one is interesting too as it points out why any "in service" tyre is at high risk of aging, whether it is used or not and that less used tyres actually age faster than frequently used tyres: https://www.liveabout.com/the-scienc...-aging-3234377

My Jaguars are summer cars and I never wear out tyres. However, I'm happy enough to swap out tyres every 6-8 years or so, as one, I don't know how far tyre-aging has gone and two, I get refreshed tyre performance with the latest tyre design more often which makes the car more enjoyable to drive when I do drive them.

I have had quality tyres go really hard and noisy in less than five years, enough to think there was something wrong with the drive train and I have had a winter tyre that was kept a bit too long suddenly lose grip. One winter it was fine, the next winter and the first dusting of snow, the tyres just about didn't work at all. I was lucky! So now, I would ditch any old tyres before it takes me near those marginal areas, especially as they are aging from inside out!

I store my XKR all winter long, too. Why not replace this set with a HP or UHP Summer tire as I have done?

My Audi A8 is my daily driver... I have a set of dedicated summer tires/wheels and a set of dedicated winter tires/wheels. The car performs at maximum capability throughout the year. I do this for safety reasons, not adolescent street-racing intimidations. As indicated above, I want to be able to maneuver away from the bald-tire demolition derby contestant.

Being an Akron, Ohio native, tires are in my blood. They are the only thing connecting you to the road. Compromised or less than ideal tires can negate every other aspect of any otherwise perfect car.

Very useful information! Thank you. It is pointed out the oxygen in the compressed air that fills the tire is essentially the promoter of internal tire degradation. That begs the question--could we not preserve our "low mileage" tires better if we filled them with nitrogen gas instead? I always thought that N2 was a gimmick/ploy like undercoating. But maybe it has some actual long term benefit.

It depends how you drive your car. As tire ages, rubber hardens and you have less traction. This process is gradual, with tires eventually becoming dangerous to drive on in a spirited manner. Think of old tires like driving in a rain.

Apparently yes, up to a point. There are a few papers out there that have looked into this and suggest some longevity benefits but it was not quantified. Also every top up needs to be with nitrogen for it to have any long-term meaning which adds cost and hassle for this currently unquantifiable benefit. Even Nitrogen permeates through the rubber but not as fast as oxygen. Personally, that money is better spent going on new tyres sooner. Tyre performance is continuously improving. Every time you buy a good set of tyres, you get a free little upgrade in overall performance of the car, be it in comfort, noise, ultimate grip or safety margin in the wet. And that is not taking into account how much performance or safety you lost as the old tyre aged.

Here, for my XKR, I need to shell out about 1200€ for a set of very good tyres. If they last 6 years, that is only 55 cents a day. If I ues them for 8 years instead, it would be 41 cents a day but I should be using nitrogen for all top ups which would eat into my savings. So I'm not going to worry about it and just think about replacing every 6 years or so if all is well. However, these day, with the amount I use the weekend cars, a couple of years might go by before I get around to ordering new tyres!

I usually would look at small cracks especially in between the treads. Also the ride quality changes along with the sound of the tire at speed. 6 years is a good rule of thumb but mileage also is a gauge. I was doing about 2500 miles a year and always parked in an unheated garage. I had also found the OEM Dunlops were only good for about 15 to 20K miles so I had to change them. But if anyone wants to take a chance of a tire failure while driving so be it.

Most recreational vehicles have the tire issue, also. Michelin came out with a 10 year replacement recommendation about 7 or 10 years ago for those tires. When protected from UV light and excess ozone, those tires still look new after 10 years. Michelin's site also states a 10 year replacement for passenger tires.

I ALWAYS use about a 76% nitrogen mix when I fill all the tires I own, be them on the Jag, my truck, motorcycle, or even my lawn tractor. Without fail. Even my basketballs get 76% nitrogen.

What comprises the other 24%? That's less nitrogen than in regular old air...

https://cimg0.ibsrv.net/gimg/www.jag...4992e53772.png

Oh, wait, were you trying to make a joke? :icon_denk:

For her birthday, I got my ex-wife Watson a silver bottle filled with nitrogen. She was puzzled and asked why, so I told her "Elementary, my dear Watson!"

NAg :icon_fryingpan:


:icon_clapclap:
P.S. In case you don't get it, see:
https://pubchem.ncbi.nlm.nih.gov/periodic-table/

OK, Stuart, you made me do this...