I have a 2010 Nissan Frontier, 4WD. 97,000 miles. Two weeks ago a black substance began to appear on the left front wheel. There is a little bit of it on the right front wheel, none on the rear wheels. It is a very thin film. You can see where I wiped some off with my finger.

[Linked Image from i.imgur.com]

Four weeks ago I had new, aggressive mud grip tires installed. Could this be some kind of film coming from the new tires?


[Linked Image from i.imgur.com]