For a while I was using my Citi Premier card at 7-11 because they were classifying it as a gas station and giving it 3x miles.
Then the Amex Gold card was classifying it as a supermarket/restaurant and is giving 4x miles.
However on the gold card when you use the new self checkout it will only give you 1 point because it doesn’t classify it as an in store purchase. I’ll check with Citi this week.