This was pretty interesting so thought I would share. Here are my results @ £1.38 I paid this morning:
-------------------------------------------------
To fill your tank you pay: £75.90
You pay £0.38 more than average in your country
Without tax, you would only pay £31.35

-------------------------------------------------
Most expensive
In Italy you would pay £6.99 more
-------------------------------------------------
Cheapest
In Venezuela you would pay £75.35 less

@ Venezuela, 55p to fill up my tank.