It will make a noticeable difference but “big” is a ultimately a value judgement. Cars are small potatoes compared to industrial polluters. Huge companies that are actually meaningfully responsible for waste have been trying to put the blame on individuals for decades. Like in a tiny sense they have a point because they’re delivering products and services to individuals but they’re also pushing all the externalities of their waste onto individuals who have very little power to make systematic change while making sure that we can’t act collectively through government.

Non-energy example: trash. Jesus lord I am swimming in trash. Not because I consume in excess but because the everyday things I need come with stupid amounts of packaging that I can’t give back to them and isn’t recyclable or reusable.