Tyre dust on rear wings?

[AC Ventura]

My MK IV has 15" wheels and recent 275 Avon ZZs on the rear, which have now done about 1500 miles. From day one, I've noticed black dust on the lower half of the rear wings, that surely can only be from tyre wear? The car tracks true and no other issues.
   Does everybody else who runs Avons experience this, or do I need the f/r geometry reset?

[silty]

No such dust experienced with me.

[westcott]

Depends on your driving style. All my cobras had black rubber powder under the rear wings if i pushed them a bit, with semi slicks or soft Pirellis even more.

[AC Ventura]

quote:Originally posted by westcott
   
Depends on your driving style. All my cobras had black rubber powder under the rear wings if i pushed them a bit, with semi slicks or soft Pirellis even more.
   

   
   Thanks for that but it's a standard car and it's not from wheelspin / drifting. It almost looks like brake dust, but can't be that. When you look, vertically down over the wing you can see this back covering/shadow. Maybe it's just road dirt....but it always seems present, even just after 50 miles.

[westcott]

What i mean is real rubber powder, not comming from spinning wheels but from good torque and sticky tires.
   
   You can wipe it away with your hands and you feel that it is rubber.
   
   My car is a early MK IV with the original Konis, just a bit better torque from the engine and cheap Toyo semi slicks, had the same powder with standard tires as well.
   
   As long as i cruise arround or drive "normal" no black dust / powder is visible.