I lived in Australia for a few years and I knew that they sold gas (LPG), diesel and petrol in stations.
I am not a car expert, but it seems that when you buy your car in Australia, you need to ask if the car runs on gas, diesel and petrol.
When it comes to English, in many countries, people say "fill up with petrol" but American people might say "fill up with gas (petrol)".
In the USA, do you say "my car runs on LPG gas" or just "my car runs on gas" if your car runs on liquefied petroleum gas (LPG) or autogas that is liquid compressed from gas air used for cooking?
Some people in the USA say "my car runs on propane" but "propane" doesn't sound like an easy word.