For the last couple of years, I've implemented a weird strategy to insulate myself from wild swings in gas prices. I never put more than $20 in my tank at a time.
I never "topped her off," but I also never got sticker shock. It was a matter of practical budgeting, of saving a few pennies by not paying last week's prices for this week's gas.
Now gas is just over $2 a gallon and my $20 goes a long way.