Low Gas Prices

For some reason, the price of gasoline/petrol keeps dropping.  This wasn't even the lowest price per gallon I saw yesterday (when it was still sunny):

To give our English reader(s) some idea: currently one dollar is 66p and 1 gallon is 3.785 litres.  So work out what that is in pounds/litre.  (By my calculation that's just under 31p per litre.  According to the BBC, the price in England is 1 pound 7 pence right now.  Fascinating, eh?)