petrol tank vs gasoline tank

petrol tank and gasoline tank both are nouns.

Word	Noun	Adjective	Verb	Adverb
petrol tank	Yes	No	No	No
gasoline tank	Yes	No	No	No

As nouns, petrol tank and gasoline tank are synonyms defined as:

petrol tank and gasoline tank: a tank for holding gasoline to supply a vehicle

Other synonyms of petrol tank include gas tank.

petrol tank (noun)	gasoline tank (noun)
a tank for holding gasoline to supply a vehicle	a tank for holding gasoline to supply a vehicle