Though consumers buy gasoline locally, prices for the fuel are largely determined by the global market for crude oil from which it is made.
When the price of crude oil in the global market changes — whether due to geopolitical events, fluctuations in crude supply or gasoline demand — prices that consumers pay at the pump change, too.
Read the full article here: http://blog.afpm.org/gas-prices-largely-influenced-crude-oil-prices/#.WqfLXZPwaXp