The ornamental design for a tread portion of an automobile tire, as shown and described.
FIG. 1 is a perspective view of an automobile tire, it being understood that the tread pattern repeats uniformly throughout the circumference of the tire.
FIG. 2 is a front elevation view thereof. A top plan view, a bottom plan view and a rear elevation view are identical with the front elevation view.
FIG. 3 is a left side elevation view thereof. A right side elevation view is identical with the left side elevation view.
FIG. 4 is an enlarged fragmentary front view thereof; and,
FIG. 5 is an enlarged cross-sectional view thereof taken along line 5-5 in FIG. 4.
The portion of the article shown in broken lines is for illustrative purpose only and forms no part of the claimed design.