I just noticed that the two front tires are developing those brown smudge marks. Why do those occur and how do I get rid of them? My car is not a daily driver and I use a car cover and so I just noticed.

 

I get brown smudges on the insides of my wheels (not tire) from the rotor rusting. Could be the same thing?

 

Is there a lot of turd on the roads of MD?

 

Hahaha! My first thought upon reading the subject!

We all know that there's a lot of BS a little south of there though!

 

I' believe brown marks are caused by an effect from the sun's ultraviolet radiation, and is worse on some tire compositions, and in different states. There's a pretty extensive write-up about it, and how to control/reduce it, here: http://www.autopia-carcare.com/ulwheelcargu.html

 

Or they could be scuff marks.

 

Or turd marks.

 

Brown scuff marks...sounds like somebody is running into the curb!