Do you really, really need gas money?
For starters, everyone’s situation is different, and it is key that you understand your own before assuming how others should or should not act. My situation is this: I will always have some backup money source (my parents) to cover my gas if I ever need it, so unless I am doing you a huge favor like driving you to the airport an hour away and gas is five dollars per gallon, I’ve got it covered. Seriously. You don’t need to offer. It’s really fine.
If I text my friend and say “hey, I’m going to the mall, do you want to come?” I am never going to follow up with “…ok yay! you just need to pay me back for gas money.” First off, I am not an Uber, and second, you will absolutely positively never catch me trying to profit off of my own friends. It’s weird. Also, why would I offer to drive if I “need” to be paid back for gas? I feel like that crosses the line over being considerate to starting some weird side hustle. Emphasis on “weird”.
Back to the situation-thing, if one of my friends offers to drive and I know for a fact that they paid for their car and have to pay 100% of the maintenance with no backup plan if they cannot pay it, I would not think twice about paying them for gas. I know which of my friends are in those situations, and I am fortunate enough to not have to deal with that. For this reason, you are not going to get a venmo request from me if I happened to drive us around all day.
On top of all of this, I am so grateful for my parents getting me a car and that I was even able to have a car in high school and now. That being said, my father, who works a full time job, does not need your two dollar venmo to help pay my gas bill if I happened to use money that was not my own to fill up my tank. If a friend of mine asked me to pay them gas money when I know their parents pay for it, I would laugh. For real, where is that money really going?
Overall, if you are in the situation where you do not really, truly, 100% need the gas money or if you are not doing some big favor, you should not be expecting the people that ride in your car to pay you back for gas money.