fuel line vs gas line

fuel line and gas line both are nouns.

Word	Noun	Adjective	Verb	Adverb
fuel line	Yes	No	No	No
gas line	Yes	No	No	No

As nouns, fuel line and gas line are synonyms defined as:

fuel line and gas line: a pipe that carries gasoline from a tank to a gasoline engine

Other synonyms of fuel line include petrol line.

fuel line (noun)	gas line (noun)
a pipe that carries gasoline from a tank to a gasoline engine	a pipeline used to transport natural gas
	a pipe that carries gasoline from a tank to a gasoline engine
	a queue of vehicles waiting to purchase gasoline