auto tire vs car tire

auto tire and car tire both are nouns.

Word	Noun	Adjective	Verb	Adverb
auto tire	Yes	No	No	No
car tire	Yes	No	No	No

As nouns, auto tire and car tire are synonyms defined as:

auto tire and car tire: a tire consisting of a rubber ring around the rim of an automobile wheel

Other synonyms of auto tire include automobile tire, rubber tire.

auto tire (noun)	car tire (noun)
a tire consisting of a rubber ring around the rim of an automobile wheel	a tire consisting of a rubber ring around the rim of an automobile wheel