Old tires might not be as dangerous as you think—if you store them correctly
Of all the parts of your car that deteriorate from literally existing, tires are the most talked about. Ask a dozen folks at your cars-and-coffee group about tire age and you’ll somehow get 14 differing opinions about how seriously to take the aging of the rubber that connects your car to the road. It’s a legit safety concern, but generally the discussion will boil down to someone citing “something they heard from a friend a while back.” Luckily, Ari Henning took a deeper dive into answering the question—and he even put his body on the line to find out.
This video was distinctly aimed at motorcycles, but there is a point at which tires are tires, and all our vintage cars have tires that get used about as much as most motorcycles. That means we should really look at this research and study it to glean a bit about our rubber too, and there’s plenty to learn.
The most common thought—and even I am guilty of this—is that tires should be replaced after five years even if they still have tread and appear serviceable. Ari asks the hard question, though: Is that a myth put out by the tire manufacturers to sell more tires, or simply a misunderstanding?
To resolve the first part of that question, he called some tire manufacturers and asked. The short answer is that it’s not that simple. Tires do age, but because that aging is due to a myriad of factors and is a safety concern, tire replacement guidelines rightfully fall on the conservative side. Five years, however, is a little too conservative. Only one producer, Avon, recommended anything close: seven years. Other brands—Bridgestone, Michelin, Dunlop, and Continental—agree that 10 years is the maximum lifespan for a properly maintained set of tires. That seems like a crazy number, but Ari decided to put his money where his motorcycle is. He found a 7-year-old set of Bridgestone RS10 tires, mounted them on the wheels of a GSXR1000 track bike, and put them to the test to see if it they would stick or slide.
Surprisingly, not only did his bike stay upright, but the “ancient” tires had enough grip to keep a pace similar to that of a brand new set. It’s not surprising. Why? Mainly because those old tires were stored properly. Here are some storage tips not just for motorcycle tires, but for your car’s tires as well.
Keep your cool
Tires should be kept in a cool place. Heat makes the oil in the rubber compound rise out, and thus makes them turn rock hard faster.
Oxidation is the enemy
Oxygen is necessary for life, but it also can kill a lot of things we hold dear—tires included. The elastomer molecules in tire rubber compounds get harder and weaker when exposed to oxygen. Sadly, there’s not a lot we can do here short of putting our tires in a nitrogen-filled bubble.
Hello darkness, my old friend …
Ultraviolet exposure also serves to degrade tires, and thus the best storage solutions are out of the sun. If necessary, resort to a black trash bag. There’s a reason you see long-parked RVs or trailers with tire covers. It really does help.
Say O-no to Ozone
A byproduct of combustion or oxygen being exposed to electrical current, ozone is the leading cause of dry rot in tires. That means storing tires in your workshop might be the worst place, compared to a crawlspace or basement (assuming there are no appliances in that basement.)
Don’t stress it
Mechanical stress is just a fancy way of saying carcass flex. It’s unavoidable when a tire is mounted and in use, but when storing a tire—like your winter tires or a spare set—it is best to not stack them, as that puts additional stress on the one at the bottom.
There is nothing you can do to completely halt a tire from aging, but with a little careful attention you can maximize the life of your tires and get the full long life they deserve. After all, it is a good bit longer than any of us thought.
i have a set of 4 tires that are?20+ years old jook good no cracking hold air well have not been on over 60 mph in over 6 years. would u say these tires could be driven ao highway speeds saftly?
I have heard several stories of newly manufactured tires (two-three months old after manufacture) that have blown apart and ruptured, causing major accidents, injuries, and several safety recalls. I really think it’s a good idea for any tire to be inspected monthly for tread groove cracking, sidewall cracks, or sidewall deformations, regardless of age. Tires do like to be ‘lightly’ oiled with a non-synthetic base oil, once a year. Don’t use any synthetic based oils, don’t use motor oil with harmful detergents and additives, and don’t use petroleum based oils or jellys (synthetic can actually dry rubber out faster, motor oil has cleaning detergents that act like thinner, and petroleum jelly can cause rubber to swell or weaken molecular rubber bonds). You can use mineral oil, plant based (olive/shortening), or animal based (lard). Think of your skin…oil it and it stays strong and doesn’t crack in the dead cold, dry winter, or extreme desert heat – the same is true with tires. More is not better either – I don’t apply too much oil as I could cause interior separation of the rubber from the sidewall interior ply cloth…a very very light coat once a year is all I require. I have a rare collector car, which gets maybe 4,000 km put on it yearly. To keep my tires flexible and extend their life for many years I have done the following.
1. Before having the tires installed in the first place, I have oiled the inside of each tire before the installation onto the rim. Again, I rubbed a “light coating” of oil onto the inside of the tire. This should help protect the inside against chemical oxidation over time. As well, the organic oil will slowly be absorbed into the rubber, working its way through the rubber from the inside out.
2. Also, I have had them filled with nitrogen instead of regular air to eliminate O2 altogether on the inside of the tire.
3. I also apply, at the time of winter storage, a very light coating of organic oil (mineral oil works well) on both sides of the sidewall. I get the inside sidewalls by sliding under the car.
4. I park in a garage, and have invested in a good car cover. I park in the shade when possible. UV destroys rubber quickly over time so I try to limit my tire’s exposure to sunlight.
5. Although I have been tempted to keep my tires at 36-38 psi, to try to save fuel, this stresses the rubber…so I try keep my tires at 32 psi to reduce molecular stress and I follow my tire’s load rating. If it’s not rated XL then your tire already has weaker sidewalls and shouldn’t be over stressed, especially taking sharp turns and cornering at high speeds. I purchased performance tires that are rated XL (load). According to many, they are better on vehicles that will sit for longer periods of time – the rubber is thicker on the sidewall and has greater strength. Most performance tires are XL but I specifically looked for this. It does increase the rolling resistance so this doesn’t make sense for my regular everyday commuter car but does on my collector seasonal vehicle because I don’t care about spending $2.00 extra per tank due to less efficient tires. I’ll save more by not having them deteriorate and needing to replace them every 5 years.
6. I purchase a tire that has silica added in its rubber compound – silica is added to keep the tire flexible at lower temperatures. Silica promotes tire and rubber longevity but because of this a tire’s tread life is less (60,000 km versus 100,000 km). Many winter, performance, sport, and race tires use this rubber additive to make the rubber more flexible, improving dry/wet traction. For a tire that is getting stored every fall/winter/spring season and that I want to keep pliable and strong for possibly 15-20 years this serves my purpose, and makes good sense since i’m only putting 4,000 km per year. again, if I was purchasing tires for my everyday vehicle that might see 100,000 km over three years I’d get tires with a much higher tread life rating and warranty, and use winter tires when the temperature falls below 10 degree Celsius. These higher life tread tires often do come at a cost though – chiefly less grip, especially at temperatures 10 degrees celsius and below. This is why winter tires are recommended for any temperature below 10 degrees celsius, and why I also use them on my regular, everyday vehicle. The province of Quebec, in Canada, has made it the law to have winter tires on your vehicle in winter, and the fine is steep for not having them installed from December 1 to April 30. It’s actually illegal to have anything but winter tires installed during this time…except if you’re not a resident of Quebec but are travelling there say from Ontario.
7. When I store my vehicle over the winter. I raise the vehicle on jack stands with the tires off the ground, and the tires are lowered to 20 psi. This helps the rubber to relax. I don’t release the pressure completely for two reasons: firstly I don’t want the tire bead to break connection with the aluminum rim or it could develop a small leak, especially if some sand or enough dust gets in there, and I don’t want the tire to undergo pressure fatigue. Pressure fatigue is not unlike metal fatigue in an aircraft – the more an aircraft lands and then takes off again, and flies at 30,000 feet the more its skin and frame are stretched and become fatigued, eventually causing metal fatiguing to the point that the aircraft must be scraped. It’s like bending a coat hanger back and forth by a centimetre each time…at some point it breaks. The same is true with a tire. If an aircraft could take off once and never land again it would last forever! It’s only because of these extreme pressure cycles that aircrafts become unsafe. The same is true for your tire. I lift them off the ground to prevent rubber radial memory and take some pressure off but I don’t put it through a complete pressure cycle.
Hagarty.com insurance, has posted an interesting article about older motorcycle tires, and it suggests rubber doesn’t become unsafe if it’s stored correctly. I would go one step further and say, lots of considerations go into making tires last longer – how long they last and remain safe depends on the tire’s construction its self, rubber chemistry, its storage, and its protection from oxidation and UV.
Hope this helps!
I bought a 1995 Corvette with only 7600 miles on it. the tires are Goodyear Eagle’s. They look brand new. No cracks. The car was stores in a heated garage. Are these tires safe to use?
Is it worth your life to risk it
Tires can degrade from inside the tire. I had a blowout on a tire that was 12 years old. Inside the rubber was turning to powder and getting thinner and thinner till the steel belts separated. There was something like a softball sized amount of rubber powder inside. The tread on the outside looked good until the blowout then there were cracks between the treads. Another sign that a tire is at the end of life is you can’t clean it enough to get it to be a dark black. Dry rubber looks like it’s a bit brown. I will not run old tires again unless it’s new old stock. I think tires can handle 10 years but then I’m just a guy with some experience. To be 100% sure follow manufacturers recommendations. Right now I testing a never used Michelin tire made in 1986. Let you know after my trip of 1000 miles. Tread separation feels like the tire is wobbly. Now you know… well… so do I. Eh, I can handle it.
Fudge YEAH! Do it man! Do it!
Hi folks.I have 16 year old, michelin pilot super sports, with, maybe 2000 miles on them,stored in a dark garage.Is it safe to use them?
Even though they are in a dark garage they have been exposed to Oxygen and this will cause the compounds to weaken and become harder on a molecular level and when combined with the constant cycle of loading and unloading (fatigue) it would put you at a higher risk of having a tire failure.
1st hot day may, or will likely, cause belt separation. I can take tires off myself and check for interior rubber turning to powder so I can test such things. That and tread cracking shows the belts will let go. Side wall cracking can just be too much sun exposure but check your treads. Sitting in acidic soil will ruin a tire. Not for everyone.
Too many variables with different tires and compounds. Recent unexpected and unusual loss of grip from my 8+ year old tires with under 40k miles and plenty of tread is all I need to know to realize that I need to replace them soon. Be your own best judge for your own satisfaction and safety.
Know your stuff or more money required. I purchased a motorhome that a mechanic had done his inspection and stated that the tread was still 85-90% good. I was pleased and sort of distracted that the fact was there was some cracking of the tires that I didn’t notice right away. We drove 600kM home and I got the oil changed. When waiting I noticed cracking of the sidewalls. Small but several. I think RV dealers know that most are 10 yrs and change .It will cost us $2500 to replace, but piece of mind. I feel they should not of let me drive it away for safety reasons.
I have a 17 year old motorcycle with the original tires still on it. I don’t ride alot and have pretty low milage on it. The tires still look new, deep thread, and no cracking. I keep saying 1 more year every year. I think I’ll do it this year.
So there’s no sense in saving the original tires off my classic car I bought 30 years ago? I always thought the next person might want them for the sake of originality, with re-treading them for show purposes.
I just bought a set of brand new Goodyear Eagle winter tires, I checked the date code when they arrived, 5011, they are already 12 years old.
That’s a good point, Burl. Always check the date code to see if your “brand new” or “lightly used” tires are a lot older than you thought!
my car has sat in a garage for 34 years with new tires on it. it hasn’t been driven. the tires look good and there’s no dry rot and it still has 10/32 of tread on it so are they safe?