[968Syncro]

I always park in the garage, not straight, but a little skoot to the right for workbench access space.  Thus the front wheels are turned while parked, and I can always glance at the front tires.   Can't really see the rear tires.  This weekend I parked next to the house, and walking towards it from behind noticed the rear tires looked funny.    You guessed it, the belts are showing.    Yes, I admit being a less than perfect car guy, please don't vote me off of the forum.   :clap:

 

Went to Discount Tire today (same place for decades for all the cars).  And I think I learned some new stuff, or here is the situation.

• What I used to call "directional tires" are really called "asymmetric", i.e. they have to roll in the designated direction and thus can't be rotated side to side.
  
• We have what is called "staggered fitment" which means the front and rear tires sizes are different.  Thus our cars can't rotate tires front to rear.  (obvious).   At Discount Tire, and he said all tires shops, a car with staggered fitment automatically had the warranty chopped in half.  So if you buy tires with a 30K warranty, they will honor only 15K of actual mileage.
  
• The rear tires were showing the wear (belts) on the inside, because we have negative camber on our cars -- at least in the rear.
  
• I could have gotten symmetrical tires so the rears could be rotated -- but to me this would not be "cool", and we have to maintain our cars in a "cool" condition at all times, and I don't know, perhaps would be lower performance as well.
  
• These old tires, bought all 4 about 3.5 years ago and 24K miles ago, had a 50K warranty, Hankook, only V rated.   But very odd, the fronts are fine, the sales guy didn't even suggest anything about replacing the fronts.  Have the car for 10 years now, and so have bought tires a few times, but cannot recall at all that the rears wear so much more than the front.  And I can't recall that the rear tires wear was so much more on the inside.
  
• Wheel alignment is a bit old, about 7 years ago.
  
• The majority of my driving is "around town", we have twisty roads all around, and then in town I am always turning corners.  Some freeway driving, but only a small share of the use.  I don't street race or get on it very much at all.
  
• Have "yellow" Konis all around, and they are pretty stiff compared to the worn OEM shocks I had before.
  
• There are no handling problems that I can sense.
  

So......

• do you guys see the rear tires wear out way before the fronts?
  
• do you see the inside rear tires wear out the most because of the negative camber? 
  
• does anybody use "symmetrical" tires on their 968s?
  

Two new Yokohama YK580 and the car feels great, so it is a happy ending.

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[ds968]

Yes.

No.

No.

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[Bulti]

If I may comment a bit:


- on a rear wheel drive car, the rear tires wear out quicker than the fronts because it's through these tires that the power is transmitted to the ground. A front wheel drive cars' tires act the opposite.


- if the belts of the tire are showing on the inside and you have still some thread left on the outside of the tire, my guess is you need an allignment. A shop not familiar with the rear suspension of these cars will not get it right. Over here at least, most of them don't.


- a directional tire is meant to be used in one direction only. It has nothing to do with the thread pattern. An example would be a tire with a V-shaped pattern. Directional tires would have an arrow on them to show correct rotation.

Asymmetrical tires have a different pattern on the outside of the tire as opposed to the inside. Both directions can be used. Symmetrical tires have a pattern that shows the same pattern both on the in- and ouside. These can also be used in both directions. These last two would have the words 'outside' and 'inside' stamped on them. This way you can check if they can be used in both directions or not.

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[Ryan]

Are you sure the wife is not sneaking out at night and doing a little "drifting"?

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[flash]

all of this assumes a correct alignment:

 

actually, the rear tires wear out like they do due entirely to camber and the fact that they do not turn when the car is turning, which increases the friction on the tire, unlike the fronts which rotate.

 

the rear wheels have about twice the camber of the front.  add to that the increased width, and the aforementioned inability to turn as the car turns, and you get about 60% more friction on the rear tires than the front.

 

the rear tires will wear on the inside a lot more than the outside.  the fronts will wear a little more on the inside than the outside.

 

to answer the above questions:

 

yes

yes

yes on the white car - no on the blue one

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[Chris Vais]

It sounds from your email that you are still running the Hankooks on the from with the Yokohamas on the rear. I was told that one should never run two different brands of tires on a car as the running characteristics between makes differ. I do go through my rears faster than the fronts, but since I habitually run the same tires, Bridgestone SO4s I don't end up with dissimilar tires.

 

Always have a 4 wheel alignment done with a new tire purchase.

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[94SilverCab]

yes

yes

yes (but only for snows)

 

Jay

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[Bulti]

"actually, the rear tires wear out like they do due entirely to camber and the fact that they do not turn when the car is turning, which increases the friction on the tire, unlike the fronts which rotate."


Off course, on a FWD car, it's the fronts that wear out quicker. Just wanted to emphasize that.

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[Inkedupfatboy]

So what happens on an all wheel drive?

Just thought I would chime in here. My tires are 3 years old and only have 4500 miles on them, so I think I'm okay for a while.

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[94SilverCab]

My 968 gets new tires every 5 years regardless of mileage.

Jay

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[Chris Vais]

I own 2 Audi Quattros. the tire on one of them are symmetric so I can rotate front to rear. he other does not have asymmetric tires so I can cross rotate. It is very important to make sure that the tires on an all wheel drive car are the same diameter. If they aren't, because you haven't rotated them you can really bugger the drive train. Both cars get tire rotations every 5000 miles.

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[Bulti]

Inked - if it's a permanent 4x4 (AWD), they should wear quite evenly, but like Chris said it is still necessary to rotate them.


On a non-permanent 4x4 it depends on which axle gets most of the torque from the engine.

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[Inkedupfatboy]

Yea I figured. I was pretty specific on date codes when I ordered my tires, but Tires Plus screwed me and ordered the AW's which I didn't catch.

I don't care for them at all. I wish I would have caught the mistake earlier. It was an $800 mistake. I don't' think I agree with the five year replacement regardless. I think mileage, wear and any rot/cracking are better guides. My car is always in the garage and out of the sun so I think my tires will last more than the five year mark, but if I see cracks, for sure they are gone unless I sell the car first which I am trying to do. If I went with the five year rule, I would be buying new tires with only 5000 miles on them. Nope.

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[94SilverCab]

I understand your sentiments, but I have been known to drive "spiritedly" and I like to cut my risk as far as possible with maintenance and preparedness.

 

I wonder how many owners check tire pressure every time they drive. No, I'm not as obsessive on my DD.

 

 

Jay

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[flash]

you cannot see the degradation of the tire.  wear indicators and such are useless when it comes to the hardening of the tire.  when a tire gets hard, not only is the ride quality diminished, but so is the braking and handling traction.

 

new tires are not like old tires.  decades ago you could just look at the tire and determine its fitness.  now, with new tire technology, the performance of the tire can be reduced long before any visible signs of wear appear.  i had this happen with a set of S0-3s.  they had about 6k miles on them, but were done.  at 6 years, they had gotten hard and you could feel it in the ride, and readily tell in the corners.

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[MCL968]

I have noticed the hardness factor with my winter tires just this year. The same corner I used to take at speed now results in loss of traction in the rear. Two years ago when the tires were about 3 years old this was not the case. These tires don't get much use since they are only on for the winter months, so the difference is not tread depth or pressure. The ride is now a little harder, and the back end is a little "happier" than it was when the tires were new.

 

Needless to say, I am greatly looking forward to the summer treads.

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[flash]

yup - that's exactly what happens.  it's a really slow process, so you don't generally notice it.

 

i change my tires at 4 years max, regardless of condition.  the only thing between you and the road are the tires.  i'm not going to risk my life over such a small amount of money

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[Inkedupfatboy]

I understand what you are saying and on most levels don't disagree, but I rarely drive the car right now and it's garage kept so the sun is not beating down on them and I have not noticed any of the aforementioned symptoms yet.

 

I am trying to sell the car, so I am not buying new tires unless I have to. I am not spending any more cash on this thing unless I can't sell it or until I make the decision not to sell it and just treat it like a car. I have other priorities right now. The car is definitely on the back burner.

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[94SilverCab]

Totally get your situation Ed, this recommendation is for the Buy and Hold crowd

Jay

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[flash]

i, on the other hand, prefer to get everything done on a car before i sell it.  a car with "excuses" is a LOT harder to sell, especially if you want anything but the lower end pricing.

 

p.s. - it's not the sun that causes the hardening.  it's the cross-linking of the polymers.  this happens pretty much anywhere.

 

that being said, tires are a pretty subjective choice, and you could easily choose what would be wrong for the next owner

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