I've always wondered why they call petrol gas over there. It would make huge sense if it were actually a gas, but it's a liquid. Also even if there is a perfectly good reason to call it gas, wouldn't it get confusing sometimes when trying to differentiate between the gas used in your hob and the gas used in your car? Say you wanted a can of gas. Now, do you mean you want a petrol can, or a gas can?
I'm all for different cultures and language evolution, you want to remove the u from colour that's cool bro I get you, there be logic thar! I just don't understand this particular difference, lol.
I think like many languages, the definition of what is being used has to come from the context, but in the case of gas in a "hob" we typically say propane, which I think most Americans would understand is a fossil fuel used to power portable stoves or barbecues.
If someone told me they had a gas-powered stove at home, I would understand from the context that it would probably be a natural gas stove.