I had a discussion yesterday about how often tires should be replaced. The person who I talked to said they needed to be changed every 1.5 years. (This regardless if you swap winter/summer tires) I always thought most tires lasted 50,000 miles (75,000 km) I do about 15,000 kms/year...between summer and winter tires. About 80% are highway kilometers....

Is it correct that you should swap them out after 1.5 years regardless of wear...or can you just allow your mechanic to judge by wear?

I go by wear only, not age.

Tom

For me max is between 5 to 7 years, depending on their walls (cracks etc). I changed my 4.5 years old (that had still thread) because there were visible cracks on the sides so I was not comfortable driving in summer with them.

Maybe your friend is driving Touareg/Q7/Cayenne (they are all the same car) those are famous for eating through sets of front tires in just 5 to 10k KMs...

Well, tires degrade over time, so probably after 6 years should be changed...if they haven't worn out in the meantime. But 1.5 years seems a bit low. In fact, let me know if you plan to do this

No, and, in my view, no. The compounds used in modern tyre contruction take quite a few years to degrade, so only if you do tiny amounts of driving will you encounter that, and in any case it's usually visible as cracking of the side-walls.

As for mechanics, in my experience they tend to advise changing tyres much earlier than strictly necessary, when the tyres still have plenty of wear left in them and are well within the legal limits. Now, to be fair, if you want to remain in complete ignorance of these things yourself, that's probably not such a bad idea, but it tends often to be based on a "they're OK now, but will need replacing before your next service" approach. Me, I prefer to monitor tyre wear myself and be aware, for example, that if they're getting a little low then toe dry grip will still be fine, but I should perhaps not push as hard in rain as if they were nearly new. And often, given that I change the summer and winter tyres over myself on both cars, will make that decision at changeover time, or perhaps decide to do so sooner or later based on the wear on one set or the other.

Certainly not 1.5 years. 5 to 6 years from manufacture would be about right - to do with the compound hardening, a sufficiently old tyre will offer very little grip.

On the up side once a tyre gets beyond 6 years it will scarcely wear any more - a consequence of said loss of grip.

Asked a co-worker today and he said I should replace them after 2 years. It must be a Swiss thing. He also says that tires wear out much faster on the highway than driving in the city....which to me made 0 sense

Age is more of an issue for WINTER tires. Even though you may still have enough tread (looking at the tread indicator lines), the tires may no longer give the holding/traction you need. Winter tires tend to dry out over about THREE - FOUR years regardless of wear. For this reason, as a starting point you want to get the "freshest" tires you can when you buy them. When you buy them in the fall, you want to see that they were produced in the spring/summer of the SAME year. If you go too early in the winter season, you may be buying last year's stock.

The codes used on the tires are as follows (from Wiki):

Since 2000, the week and year the tire was produced has been provided by the last four digits of the Tire Identification Number with the 2 digits being used to identify the week immediately preceding the 2 digits used to identify the year.

Example of a tire manufactured since 2000 with the current Tire Identification Number format:

See the 5107. This means that the tire was produced in the 51st week of 2007.



Another "quick and dirty" way to check is to run with the tires and see how the control is. If you start to slip with winter tires, it is the time to change them. Same for quick acceleration with summer tires. If you slip when accelerating from a stop, it is time to change them.

Not a Swiss thing, just a thing of someone who has clearly too much money and too less brain.

Replace my summer tires when they are at/near the legal limit 1.60 mm. Winter ones sooner at ~4 mm. Or if they are older than 6 years.

TCS recommends to replace summer tires when they have less than 3mm.
. They also say you should not drive if the tires are older than 10 years. Normally a tiere is approx 1-2 year old at purchase. Do not accept any tire that is older than six years at date of purchase. See above post how to find production date.

My observation: tires wear down (not out) much faster at higher speeds. Older tires are harder, have less grip, and do not wear down as fast as new ones.

Mileage/kilometerage is not a valid measure because it depends not only on the type of drving you do but also on the quality of the tyre - cheap tyres tend to wear out faster than more expensive ones.

Wear/depth of tread is really the only relevant measure, unless you don't drive enough to wear out your winter tyres before the time issues already noted above.

By the way, the rubber in the tyres doesn't "dry out", rather it perishes, degradation of the molecules that make the rubber elastic caused by environmental factors.

Very reasonable. At 1.6mm the tire has little capacity left to efficiently dissipate water.

The "challenge" with running the tires to their "legal" wear limit is that in the event of an accident,the first thing our very nice CH police do is check the tires for wear.

If they do not like what they see, they note it on the paperwork. Then your "friendly" insurance company informs you that they will pay only a "portion" or none of the repair on your vehicle. BINGO - they got you.

To my mind, tires are a cost of running the car comparable to changing the oil. It costs, but it needs to be done. Running things to the maximum age increases the risks exponentially. Each person needs to decide where they are on that scale while at the same time being realistic about the risks they "may" be taking.

So if somebody is involved in an accident and the thread depth on their summer tires is 1.9mm, this will void your insurance?

I can understand if it is 1.7mm but if you are on the legal norm how can they contest it?

You are then going to have a discussion that requires YOU to "prove" that ALL of the tire surface of ALL your tires meets the minimum norm. Have a look at what 1.6 (not legal), 1.7 and 1.9 mm looks like. I frankly can't tell the difference.

You chances of loosing that argument is pretty high. Hence my suggestion that people don't cut things too finely. The insurance companies will use any excuse to not pay.

I do not buy new tires if they are more than 3 months old, 6 years someone is having a laugh.

Winter tires have noticeably less grip after 4 years, however I never get more than 2 years out of rear tires & 3 years out of front .

1.6000 mm -> legal, 1.5999 mm -> illegal. Just at one single spot, on one single tire. How to tell? Use (3) of this device:

The problem is that some tires have the tendency to wear down with a much more rapid rate once they are down to ~2mm. This phenomena is very prominent with some motorcycle tires.

We used to do up to 500km per week in our family car. It had annual inspections, and if we hadn't changed the tyres last year, they would definitely need to be done this year.

"He also says that tires wear out much faster on the highway than driving in the city....which to me made 0 sense"

Actually he's right...although not so much for the swiss highways where the limit is 120km/h. A friend of mine regularly goes 250+ in Germany and after a few such drives his tires are worn out

You can swap out the tires after 18 months if you have money to burn...

It certainly depends how much driving you do and what conditions the roads are in - everything from the temperature, road surface, amount of turns and stops, etc. make a difference.

On my car, a set of tires (winter or summer) won't usually last more than 2 seasons anyway. I drive around 30'000 KM per year, and a set of European tires will usually not last much more than that. (Yes, when I was living in California, we had 50'000 mile tires, but we don't have any winter in Southern California!).

On my motorcycle, I usually end up replacing the tires after about 6500 km - a normal season for me. Sadly, I didn't get much riding in last year and have only been out twice this year so far, so my tires may hold into 2013

As far as age goes, I wouldn't ride a motorcycle if the tires are older than 5 to 6 years because bike tires must be much softer and will degrade much faster. For a car, tires that are 6 or 7 years old are still OK, but I would get worried if they were 8 or more years old and had been exposed to the elements (sunlight/UV) for a long time.

That is dead on accurate advice, I would only add that it is equally important to rotate your tires so you can ensure more accurate wear through the life of the car. As with your brakes the front tires will wear out faster than the rears.

All tires also have a tread wear rating, although it is not strictly regulated that all manufactures use the same scale you can still get an understanding how soft/hard the compound is and how long the tread life will be.