Cluj-Napoca doesn't yet have a direct link to Southern California, so anyone booking business class from Los Angeles to Cluj-Napoca needs to think in terms of a smart connection rather than a single carrier's product. In practice, that means routing through Munich or Frankfurt on Lufthansa, through Istanbul on Turkish Airlines, or through Bucharest on TAROM — and the factual bottom line is that total journey time typically runs around 13.5 hours of actual flying, spread across two segments. My preference, after flying this corridor repeatedly, is the Lufthansa option via Munich: the transatlantic legs increasingly feature the new Allegris business class with sliding privacy doors on select 747-8 and A350 routings, though you'll want to check your specific aircraft since the rollout is still uneven across the fleet. Turkish Airlines via Istanbul is the other strong contender, especially for the lie-flat seats and genuinely excellent catering in their long-haul business cabin, paired with a short hop down to Cluj on a regional jet.
The insider move here is booking the LAX–Munich or LAX–Istanbul long-haul segment as the "anchor" flight and treating the final leg into CLJ as a formality — but pad your connection time in Munich or Istanbul to at least two hours, since Cluj-Napoca's small airport means fewer daily frequencies and a missed connection can cost you a full extra day. Istanbul's IST hub in particular rewards early arrival at the Turkish Airlines lounge if you have a long layover, as it's one of the more spacious business lounges in Europe and a good place to recover before the final short hop.
January through March and again in October and November are consistently the softest months for fares on this Romania-bound corridor, largely because Transylvania's tourist season peaks in summer and around Christmas markets. Given the complexity of routing through three different alliances depending on carrier, setting up fare alerts for this specific LAX–CLJ business class itinerary is genuinely the smartest way to catch the periodic dips before they disappear.
