I buy gas and diesel weekly (125 round trip to work every day) and gas has been $2.79/gal here in NH for about a month or more.
Diesel has kept going up slowly since Oct and now is $3.25/gal and has been for about 3 weeks (tough on the wallet when you have a 52 gal tank on the truck).
Location is probably the reason you’re not seeing price reduction. It’s been fairly stable in TN since the summer 2.49-2.59 a gallon. The last two weeks it dropped rapidly
It’s not how big your tank is, it’s how much you’re driving