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Discussion Starter · #1 ·
Hi all,

How do you know if the tires are due for change if there are still plenty of treads left?

We are almost in March 2015, and my tires were all made around 10th week of 2010. There are still around 1/2 the treads left. However, I do not know when they were initially mounted on to the car as I bought the car used about 2 years ago with the RE11 tires on already. So they could have been shelved for 3 years and mounted just right before handed to me.

Temperature doesn't drop below freezing temp for sure, and on only very few occasions it would dip below 50F (10C) in winter. Summer time would be looking at high 80s in F (around 30-33C) with 70 to 90% humidity.

I mean the car feels less grippy, but sometimes I wonder if that's psychological. Wondering anyone knows what's a good way to tell ... thanks
 

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Most tyre manufacturers state that tyres are past their best at over five years old. This is down to the rubber curing and as a result, they give less grip. In some cases the sidewalls can start to crack too. You can tell how old a tyre is by looking at the DOT number on the sidewall. It will be something like, DOT 2011, for example which in this case would indicate the tyre was manufactured in week 20 of 2011.
 

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Tire Rack says it depends in part on how exposed to sunlight the tire has been. (That should mean our tires here in the Pacific Northwest should last forever:hilarious:.)

In general it's fair to assume that the "5 year" limit mentioned by our Welsh friend above is stated by manufacturers both to sell more tires and to cover all legal asses. People who know tires whom I've spoken with have said that (depending on air pollution levels and exposure to UV light) in reality you're rarely looking at the need to change before 6 years--and indeed it can sometimes extend as far as 10 years (!) if there's little sunlight and low pollution levels. I think to some extent you can tell if you're way past due if the rubber is visibly looking/feeling older/drier.

I know this isn't directly relevant but I have one bicycle tire that is over 40 years old, still feels good, and works just fine. (It's been exposed to little light or pollution.) No--I'm not suggesting you should keep your tires for 40. I'm jus' sayin' . . .
 

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looks like someone has got an excuse for a track day! or to try drifting?

If you want to try something new or just bored with current set, you can always sell this set or trade them in (if they do that sort of thing in HK).
 

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In general it's fair to assume that the "5 year" limit mentioned by our Welsh friend above is stated by manufacturers both to sell more tires and to cover all legal asses.
Er hem - Englishman living in Wales, actually. ;)
 

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Considering that tire companies exist to sell tires, I must assume their 5 year life estimate is an ultra conservative one with selling tires as an added factor. Appearance and ride should be equally important. I personnally don't even start thinking about age replacement until 7 years and have had tires which look and ride just fine for longer periods. On my Porsche though I would consider that 7 year limit as time to get serious about replacement. Now if only I could not wear them out every 3 years or so I might even think longer and harder about the issue.:cheers:
 

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Discussion Starter · #9 · (Edited)
Yup. Mine are made around the 10th week of 2010 as shown on the sidewalls.

Unfortunately HK has got no where to drift and burn these things out. I was thinking of taking these with me to the track, but quite a few people think that's a waste of money and effort (it's quite expensive to do track day here, over 1400 USD realistically just for all the fees and license to drive the car to China). So driving up to the track wiry dead tires would be a waste of the track experience.

still debating whether to get another set of wheels for track rubber, as apartments are crazy small here. Might be able to borrow a set of wheels to mount some fresh rubber on. But then if mine are due then I might as well just mount the tires on mine and drive them after track

Trofeo R and Michelin Cup2 tires are out of stock at the moment. So I'm debating whether Dunlop Sport Maxx Race are worth a shot ...

I actually had a set of tires die on my after 5 years. It was so bad that the car couldn't even get up the hill in the rain even though I was extra gentle on the throttle. Felt like I was driving on ice even though it was just a bit of rain! Anyway, that was another car ....
 

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The 5 year suggestion from tire companies doesn't sound like a general thing given tire warranties that last 6 years.

Th issue of hardness in the rubber and so loss of grip is real, and I suspect there may be a formal way to check (durometer?). Another thing to check for are cracks in the rubber within the grooves. They may be surface only but can also be deep.

The inspection for sidewall cracks seems to depend greatly on sun exposure in my own experience. Maybe the OP's tires had the luxury of underground parking in HK. :)
 

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Sunlight is a factor, as is running hard and Hot for extended periods of time. My guess is u don't run for extended periods of time at high operating temperatures, because u don't have thousands of miles of rural high speed interstate hwys. So there is no way you could age your tires in 5 years, unless in the sun on them all day, every day.
 

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Good advice above. You can be sure the 5 years rule from manufacturer is waaaay on the safe side, to help them sell more. I'd say 7 years if the car is garaged and tires are not subjected to extreme colds. That's the rule I use.
 

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Discussion Starter · #13 ·
Ya. This car is parked under a cover with minimal sunlight exposure. Don't really see any cracks on the tires to be frank.

i mean these are a tad less sticky compared to the fresh set of RE11 tires on my other car, but then it's hard to compare tires on different cars at different times. I mean these tires aren't so dead that I can't even get the car up the hill.

anyway, thanks for input guys
 

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from my 2007 owners manual:

"Under no circumstances should tires older than 6 years be used on your Porsche."
 

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Discussion Starter · #17 ·
Loss of wet traction as the rubber hardens?
Yup. I experienced that on one of my other cars. Plenty of treads left, but car just couldn't even get up an off camber uphill turn at even 30km/h (i.e. 18mph) in light rain. I tend to drive that car very gently normally, so never noticed how much the grip has dropped till it rained -- it was scary.
 

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from my 2007 owners manual:

"Under no circumstances should tires older than 6 years be used on your Porsche."
OK, but does anyone actually believe that? Car company legal departments have gone crazy to the point where the little boy has cried wolf so often it's hard to take him seriously. In E90 BMWs you literally have to "agree" on the I-drive that you won't use the nav system to override reality should you see a tree in your way, etc. EVERY SINGLE TIME YOU GET IN THE CAR and they've rigged it so there is no way to permanently override the software to avoid this irritation from which BMW's legal dep't makes it clear they believe the people buying their cars are complete idiots. (One of the 50 reasons why I'll never buy another BMW . . .)
 

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Tires will obviously get dry rotted and brittle and visually you "will" know it's time to oft them!

A 5-7 year time line is a great guideline if you actually want to be sure and safe.

Safe is a debatable term for some though...anything can happen when you are @ triple digits. I don't want to worry about my tires falling apart that is for sure.
 

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Yup. I experienced that on one of my other cars. Plenty of treads left, but car just couldn't even get up an off camber uphill turn at even 30km/h (i.e. 18mph) in light rain. I tend to drive that car very gently normally, so never noticed how much the grip has dropped till it rained -- it was scary.
Wow... I've always wondered about loss of traction over time. Tire reviews are from new tires, and there's no way to know the characteristics of all the different rubber formulations used by different companies. Kind of makes tire warranties misleading.

Please let me be a little curious: was the situation the first light rain after a dry spell? I know rain is common in HK, yet I wonder about grease or other surfactants on the road surface that contributed to your experience in light rain, which doesn't wash everything away immediately. Also, was it a front wheel drive car aimed uphill? I wonder about weight being shifted to the rear and so less traction to get going. I've seen traction loss in RWD pickups with an empty bed.
 
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