Quality of Euro Diesel in Tbilisi ??

Please, anybody of you, dear readers, which Euro Diesel can I fill without regret into my car ? I almost ruined my engine twice in the last three month because of strange behavior and unpredictable quality.

Is there any quality difference at all between the big chains like Wissol, Lukoil, Socar, Rompetrol, Eko and others, or does it all come from the same tube ?

What is your experience ? What would you recommend me ?

(My car has a 3.0 DI engine)