leaded gasoline vs leaded petrol

leaded gasoline and leaded petrol both are nouns.

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

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

leaded gasoline and leaded petrol: gasoline treated with a lead compound to reduce motor knocks

leaded gasoline (noun)	leaded petrol (noun)
gasoline treated with a lead compound to reduce motor knocks	gasoline treated with a lead compound to reduce motor knocks