Tipping the gas station attendant is absolutely not expected or necessary.

Some exceptions that I typically follow:

If my windows are filthy or there’s a huge bird shit and the guy does it without even asking

If there’s a young kid there at a family owned place and he does the windows regardless of need or quality of work - “thanks buddy nice to see you hustling this summer”

Brutal cold like sub 5* F I’ll usually give a couple of bucks for them to get some soup or coffee inside

I’ve seen a bunch of replies here that they tip “their guy” during the holidays - im good with this but I don’t have a guy, I guess my spot has high turn over