Fuel Economy this Winter Has been Extraordinarily Bad. What Should I do?

[Eggman]

a couple extra bucks for a tank of good gas at a different station might tell you something, or it might not, but then you only paid a couple extra bucks

Costco sells Top Tier gas - and lots of it.

It's good stuff.

look for a station with new underground tanks and high volume sales

But how can you tell if they're underground.