Americans, Canadians, as well as citizens of Australia, New Zealand and most of the non-EU countries, do not need an entry visa to travel to Romania for stays shorter than 90 days. If you plan to stay longer than 90 days you will need to contact the Romanian Embassy to obtain a visa.
All European driver licenses, as well as U.S. and Canadian, are valid for driving in Romania for 90 days from the date of entry into Romania.
Entering and leaving Romania is free, no travel tax is charged.