If you want to find the cheapest gas in your area, you should check out GasBuddy. A couple of days ago on their blog they published a simple study they did that includes a table for the best times to buy gas by state. This table is great for looking up your individual state, but it’s impossible to see any patterns in the data.
I recreated the data in Excel and opened it up in Tableau. The first thing I noticed is that the data seemed too sporadic for me, so I took the liberty of grouping the data into four buckets: Early week, mid-week, late-week and the weekend. In less than 5 minutes, I had this map.
Now it’s much easier to see that in the majority of the US, you’re going to find the cheapest gas on the weekend. It’s much tougher to discern that from their table. Click on the color legend or the table to highlight.