VAT just went back up, and an increase in fuel duty went on as well.
OF the £1.15 per litre, about 70 pence is purely fuel duty and VAT. The actual petrol station gets about 5p, of which about half is profit for them. The remaining, roughly 40p, is:
Transport (which increases with fuel price increases)
Refining ( which doesn't change much )
The oil itself.
So - the price of the oil itself, is only one part, of a small part, of what you pay at the pump. That's why our petrol prices don't fluctuate very much - they're just very high.
IN the US - because there's far less tax on fuel - the cost of crude becomes a much much larger part of the price at the pump, thus if the price of crude changes significantly - so do their pump-prices.