If we go down to talk Economics, I would fear it would alienate some people from the whole idea of this post; reducing operational costs.
Therefore, I found this piece of information from EIA
https://www.eia.gov/petroleum/gasdiesel/
Which is a current survey and not a prediction of gas prices. If you look at the gas pump graphic, it shows percentage of composition of gas prices. A lot of these variables can be known; Crude Oil Price and Taxes. As I look deeper into other sources, Refining margins seem set but they allowed variation with season especially with the ethanol mix. However, the Crude Oil aggregate is the bigger component.
Now as we now head into $50 per barrel territory, which is the highest in three months, I wish you all a pleasant summer.