tune up vs fine-tune

tune up and fine-tune both are verbs.

Word	Noun	Adjective	Verb	Adverb
tune up	No	No	Yes	No
fine-tune	No	No	Yes	No

As verbs, fine-tune is a hyponym of tune up; that is, fine-tune is a word with a more specific, narrower meaning than tune up:

Other hyponyms of tune up include tweak, service, tune in.

tune up (verb)	fine-tune (verb)
adjust the pitches of (musical instruments)	adjust finely
adjust for (better) functioning	improve or perfect by pruning or polishing
	make fine adjustments or divide into marked intervals for optimal measuring