That's makes more sense than my theory because I did not shine that tire when I cleaned it up once and to think of it the stains re occurred.Blastek said:apparently this is from some oil they put on the threads on the spare tire. at least that was the conclusion the last time around
I was getting ready to post this exact same thing. Scrub the tire with a good degreaser and it will stop. Or like mentioned above, trade it with a tire you got a couple hundred miles on. All new tires have a release agent. It's oily.It IS the release agent from the tire. Keep the bumper clean or it might stain it.
It will go away after about 3-4 months.
Or you could rotate your tires sooner.