Problem with tire ding?
 

<center><img src="http://pictureposter.audiworld.com/13113/tire_ding.jpg"></center><p>Looks like someone backed into a curb :( ... skinned the edge of the rim and pulled a flap on the side of the tire wall. Does this weaken the tire significantly? I'm worried because it's in the sidewall. Total thickness of the piece at its deepest is 3-4 mm.

hard to tell from the picture, but better safe than sorry ...
 

i'd replace it if i were you -- it's not worth the risk of a blowout at 80 mph.

Replace it. That will eventually fatigue, and fail. As to when, who knows?

You can't repair the sidewall of a tire. It's a high stress point; unfortunately, I'd replace it.

Ditto on replacement. (m)
 

Like TedK said sidewalls cannot be repaired due to the high cornering stresses that they undergo. Given that same issue, since the sidewall is damaged you have compromised the integrity of the tire, alas, you should replace.

Call me if I can help with them!