Tenn. Code Ann. § 55-1-110: "Metal tire," "pneumatic tire" and "solid tire" defined

(a) "Metal tire" means every tire, the surface of which in contact with the highway is wholly or partly of metal or other hard, nonresilient materials.

(b) "Pneumatic tire" means every tire in which compressed air is designed to support the load.

(c) "Solid tire" means every tire of rubber or other resilient material which does not depend upon compressed air for the support of the load.