police car vs police cruiser

police car and police cruiser both are nouns.

Word	Noun	Adjective	Verb	Adverb
police car	Yes	No	No	No
police cruiser	Yes	No	No	No

As nouns, police car and police cruiser are synonyms defined as:

police car and police cruiser: a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters

Other synonyms of police car include cruiser, patrol car, prowl car, squad car.

police car (noun)	police cruiser (noun)
a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters	a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters