Enjoy your trip to Romania.
It is important to know that the price of gasoline in different countries varies from time to time. The price in my answer is updated at November 2014.
The average price for 1 liter of gasoline in Romania is 1.70 U.S. dollar.
Time of Check: 04-Aug-2014 to 10-Nov-2014.
The minimum price per liter of fuel in Romania for that period was 1.63 U.S. dollar.
Maximum price per liter of fuel in Romania for that period was 1.76 U.S. dollar.
For the most up-to-date price see link - See link
The average price of gasoline in the world for this period (04-Aug-2014 to 10-Nov-2014) is 1.25 U.S. dollar.
Gasoline price in Romania is more expensive than the average price for gasoline in the world (0.45 U.S. dollar more).
Did you know that Venezuela has the world's cheapest gas, sold at government filling stations for 1 cent a liter?
Did you know that Norway has the world's most expensive gasoline, at 2.26 U.S. dollar per liter?
Car rental in Romania
Car rental SIXT Romania (Locations and Branches, types of rental cars etc. ) - See link
Car rental AVIS Romania (Locations and Branches, types of rental cars etc. ) - See link
Car rental BUDGET Romania (Locations and Branches, types of rental cars etc. ) - See link
Maps and navigation apps for Romania
Map of Romania (Google Maps) - See link
Google Maps app for Android phones and tablets - Link
Google Maps app for iPhone and iPad - Link
Driving in Romania using waze app for Android phones - Link
Driving in Romania using waze app for iPhone - Link
SOURCES OF INFORMATION
IEA - International Energy Agency - link
Gasoline prices in globalpetrolprices.com - link
Gasoline and diesel usage and pricing - link
What determines the price of gasoline? and more FAQ - link