Unlike two tanks ago, I put in lots more gas. Well, only about 0.3 more gallons, but the 11.552 gallons confirmed to me that the Sheetz from last time did indeed shut off too soon, and it made this tank's fuel economy look as bad as last tank's looked good. 35.15 miles per gallon. Just pitiful. Worst mileage since August 2010!
To make things worse, I forgot that I needed to get gas this morning so I didn't leave extra early, so in my haste to get to work I went almost over the speed limit! Fortunately, I drafted behind a giant tractor trailer hauling what appeared to be two large dumpsters. Unfortunately, it became evident that the dumpsters were filled with dirty diapers and rotten eggs.
I changed the oil in the car last week, and as I was lying underneath the car watching the oil drip into the collection pan, I remembered hearing that there's a new car(s) out there that has louvers that shut when the car goes at highway speeds, in order to better manage airflow and increase mileage. Then I remembered some hacker website where a guy put duct tape over his grille and such to simulate this effect, and it improved mileage.
There's an area at the bottom of the bumper, below the grille, that just looks like it's holes for air to blow through, it's below the radiator. So I'm thinking about finding some duct tape myself and covering these holes to see if mileage improves at all.