The price of gasoline can change on any given day. Although a number of factors determine the price per liter, the price of crude oil makes the most impact. The per-barrel price of crude oil is most directly affected by world supply and demand. By closely monitoring the price of crude as well as keeping tabs on a few other factors you can estimate the cost to fill up.
Divide the crude oil (Moving Average) price by 159. One barrel of crude contains 159 liters. This will tell you the dollar amount per liter of refined gasoline attributed to crude. For example, if crude oil is $100 per barrel, then about $0.628 of the price of a liter of gas comes from the crude price.
By multiplying this amount by Dollar/Turkish Lira, special ratio and upper limit, you can get an estimated price per liter.
For example: using $0.628 , multiply by USD/TRY (17 TL), Special Ratio (2.1) and Upperlimit (1.03). An average cost per liter of gasoline is 23.09TL