Gothenburg rarely gets the transatlantic glory that Stockholm or Copenhagen enjoy, which is precisely why seasoned travelers treat routing options here as a puzzle worth solving. There is no nonstop option, so business class from San Diego to Gothenburg means connecting through one of three credible European gateways: Frankfurt or Munich on Lufthansa, Amsterdam on KLM, or Copenhagen on SAS, with total journey times typically running 15 to 18 hours including the layover. My preference over dozens of crossings has settled on the SAS routing via Copenhagen, since SAS operates the short Copenhagen-Gothenburg hop frequently enough that even a tight connection rarely becomes stressful, and their A350 business class on the long-haul segment offers direct-aisle-access reverse herringbone seats that rival much pricier European carriers.
Lufthansa's Munich connection deserves consideration too, particularly if you can snag one of their newer Allegris-configured aircraft on the San Diego–Frankfurt or Munich sector, though Allegris rollout remains inconsistent enough that you should check your specific aircraft before booking based on that seat alone. KLM's Amsterdam routing, using their World Business Class on the 787 or A330, tends to offer the most schedule flexibility for connecting onward to Gothenburg, and Schiphol's transfer process is famously efficient even for tight layovers under 90 minutes. My insider tip: fly westbound (Gothenburg to San Diego) through Copenhagen rather than Amsterdam or Frankfurt if you can, since Copenhagen's security and passport control for transiting US-bound passengers moves noticeably faster during the 7-9am departure bank, saving you real time versus the more congested German or Dutch hubs.
Deal-wise, May through September consistently produces the softest business class fares on this corridor, as Scandinavian carriers compete harder for summer leisure traffic while corporate demand into Gothenburg's automotive and shipping sectors dips slightly. Award space and discounted J fares appear and vanish quickly on this thin route, so setting up automated fare alerts for San Diego to Gothenburg business class is the smartest way to catch a favorable pricing window before it closes.