WHAT DO I PAY FOR PETROL? WELL I PAY ABOUT....
Right, sorry... I guess I caught the fever too. Anyway...
What you call "petrol" we call "gasoline." Where I live we pay 1.98USD/gallon. This is about as high as I've ever seen gasoline priced in my entire life. This works out to about 0.52USD/liter (since 1 gallon equals 3.8 liters.) In Australian dollars this works out to about 0.68AUD/liter at the current exchange rate of about 0.77AUD to 1.00USD.
Saying it in Aussie
Wherever, AUS - 1.20AUD/liter
Maryland, USA - 0.68AUD/liter
Saying it in American
Wherever, AUS - 3.51USD/gallon
Maryland, USA - 1.98USD/gallon
I don't know the answers to any of your other questions, except that our prices haven't really changed much since this time last year that I can recall.