Petrol prices have been tumbling here in the UK too. They were about £1.10/litre a month ago, now they're predicted to be 87p/litre by Xmas. Good news for me, since I get my car back at Xmas. Yay!
Unfortunately, due to tumbling prices, the government has put up duty and tax on petrol to compensate. Boo! Bad Labour! Bad unelected government with no mandate! Go to hell and die you evil people!