I don't think it is ignorance, just colloquial terminology coming into play.
I am curious though, is the USA the only place that calls it 'gas'? I've lived and travelled through most places in Oceania, Asia and Europe and almost everywhere else it is called 'petrol' and places that serve it are called 'petrol stations'. To me 'gas' is an entirely separate product, viz LPG gas, which a lot of taxis etc. use at the moment.
I am curious though, is the USA the only place that calls it 'gas'? I've lived and travelled through most places in Oceania, Asia and Europe and almost everywhere else it is called 'petrol' and places that serve it are called 'petrol stations'. To me 'gas' is an entirely separate product, viz LPG gas, which a lot of taxis etc. use at the moment.