Kerosine
Not much avgas in Romania but some is available.
Dorin Ivascu is MD of Baneasa airport (Bucharest) as well as the operator at Tuzla Airport, a grass aerodrome not far from the bulgarian border on the coast, much nicer than Constanta. He s the best contact to find out about routing, assist in CAA permissions and advice on avgas availability.
PM me for his email.
Bacau I ve not flown to, Iasi (no avagas) is a good hard runway and a pretty town on the Moldavian border. Same at Sibiu and Timisoara.
Strejnic i hear now has a hard runway, just north of Bucharest, west of Ploiesti
Some polish are currently doing some VFR via Romania to Turkey, I have their email for their experience. pm me