Hi, if you are talking about fuel they mean the same thing. In American English gas is typically used, in British English (including Aus and NZ), you'll hear people say "my car needs petrol".

As others have explained, it's a difference between U.S. and U.K. To this, I would add that in the U.S., "petroleum" is the raw unprocessed mineral substance found in the earth. If you put it into you car (if that were even possible), it would immediately destroy the engine. We also use the term "petroleum distillates" to refer to the broad category of all products that are refined from petroleum. Gasoline is but one of many petroleum distillates. You could say that you are putting a petroleum distillate into your car, and it would be true, but nobody ever says that.

If we are using these two words in the context of a Gasoline/Gas/Petrol Station...... Then I can tell you I had never heard the word "petrol" until I visited England. In Colombia, South America "gas" actually meant pumping "gas" in your car, they have a hybrid system that actually uses gas (not gasoline) as a fuel as well as in Brazil. That really blew my mind, and they make everyone exit the car for safety issues cause the car could explode (at least that was the answer I got). You will never hear a North American person use petrol but rather petroleum, and they use the word petroleum in a more scientific context meaning the source in which "gasoline" is made or extracted. So if you are in the USA and you need fuel for your car just say "I'm running low on fuel" or "I gotta get some gas". Sounds funny in retrospect. Hope this helps.

Gas can be any substance that is neither liquid nor solid. Petrol is the fuel which is used to drive motor vehicles.

Yes and no. Gas is used for heating homes. (Town gas or other forms of gas) Gas is a term for Gasoline and widely used in American English for Unleaded Fuel for cars. Petrol (same thing) is used in British English for Unleaded Fuel for cars. Hope that helps, Kat the teacher