No. Find a rim profile, draw the curve and revolve it. For the tire, same sort of thing...draw a profile (using the rim profile as a guide for placement) and loft or extrude it. Convert to polys, and start modeling the treads for one section. Then duplicate the section over and over and merge the verts/edges until you have a long flat tread. Then use a bend modifier to bend it 360 degrees for the tire.
Or you could draw your tire profile and revolve it like the rim and use a displacement map for the tread....whatever floats your boat but yes....two seperate pieces.
"Terminat Bora Diem, Terminal Auctor opus."