ajg617

Well, I'm asking this question because I purchased a set of Continental DWS Extreme Contact tires this time around. Just wanted a slightly more aggressive tread for winter use. But after 7K miles, the outer sipes on both front tires are worn half way at the back edge of the each sipe. The overall tire wear is even, 7-8 32nds across each tire.

Been using Conti ProContact tires for years on this car and never had this problem before. So I contacted tire rack and they contacted Continental who told me to take it to the local VIP store. No surprise there, he noticed the wear bounced the front end up and down and said I needed new struts. Ahem, he even said Audi recommends replacing the struts every 50k miles which was news to me.

So, there is absolutely no sign of any leakage or staining anywhere on the front struts. There is no noise when hitting bumps. The car doesn't bounce up and down, tracks straight, turns like it should, and rides nicer than my C6.

I've run into this problem before - in fact with all 3 Suburbans. On a heavy vehicle like that, I would get exactly the same tread wear pattern on Michelins, Goodyears, etc. when the gaps in the outer sipe tend to be angled like the DWS. If I went to the more standard less aggressive tread pattern, problem disappeared. The UTQG on both the DWS and ProContact are very close. My own theory is that the wear is particularly brutal on high speed clover-leafs, and I have to use a few of those each day and in each direction.

So, how do you really tell if the struts are failing/have failed? I driven cars with bad shocks on them and knew it right away (even drove a car with no rear shocks on it in the 60's waiting for special order ones to come in - not recommended).

SloopJohnB@mac.com

pic of wear pattern?

http://www.johnsontirecenters.com/at...redownload.jpg

or

http://www.monroe.com/images/support.../tirewear6.png

or

http://www.monroe.com/en-US/support/Symptoms/Tire-Wear

??

ajg617

Neither really. If you look in the attached picture of the outer sipes, there is a 1/32 difference between the top inner edge of each outer sipe and the bottom inner edge of each outer sipe (at the first groove). So if you run your hand from front to back across outer edge of tire, you can feel the sharp forward edge of each sipe. If you run your hand from back to front, it feels smooth. So, forward edge of sipe is 1/32 higher than trailing edge. On the first section of tread inside of the first groove, it is smooth all the way around and measurements are consistently the same across the entire width of each tire. The inner sipes do not show this wear pattern.

Tires are wearing quickly as well. In 7k miles, down from 10/32 to 7/32 across all four tires so I can expect to see about 21k out of them at that rate - far too soft. Should note that the two front tires were replaced by Continental because the originals exceeded road force tolerances. The replacements (those on now) gave me an immediate sharp pull to the right which I assume is the result of the a radial bias on one of the tires. Either switching right to left or rotating front to back corrected that problem.

jcman

I had the same issue on new set of Yoko's at about 5k when I adjusted tire pressure 5 psi higher still after two seasons the wear is normal, I had the thought as you at that time but then my car had 50k on the clock.

ajg617

High speed curves are a killer. 17K out of Yoko Avids before switching to the Conti ProContacts. I think the issue is when the sipes are not connected near the first groove (they are on the ProContacts but not on the DWS), there is too much movement of the disconnected sipes especially on the outside tire around the curve. Hence no real wear on the inner sipes, just the outer. If you drive in a straight line it's probably ok. But all the curves just wear them down.

jcman

Agreed that high speed curves are a killer on any tire with front weight these cars carry, when I drive my garage queen that I average 4k a year on I generally drive it like I stole it but then I have the 100lb less advantage with the aluminum 3.0 and uprights along with the 17' wheel option.