I'm on the Omio site trying to book transportation from Stockholm to Oslo. It looks like the train to Gothenburg and then the bus to Oslo is faster than the direct train to Oslo. Anyone know why? Will this change later in the summer? We're not going until August.
Neither Google Maps nor DB Bahn nor Omio nor SJ is showing what you saw. All have train listings that show a slightly shorter time with no train change directly from Stockholm Central to Oslo S on July 6. Try using your exact dates in August. See below for track work planning issues that may affect what you see. I edited it slightly.
From SJ (https://www.sj.se/en) they are:
06:08 - 13:14. Travel time 7:06 h
SJ High-speed train, SJ 3000, Train 623
14:12–21:24. Travel time 7:12 h
SJ High-speed train, SJ 3000, train 639
When does SJ release their tickets?
You can book tickets for the period 30th of Mars 2023 - 3rd of September 2023.
Some departures are blocked due to track work planning. The departures will be released for booking as soon as the planning is complete. The tickets will be released continuously every day. SJ Customer Service cannot give any information in advance about when a specific departure can be booked.
At the moment, the Swedish Transport Administration has extensive problems with its planning of track works and thus giving notice of which trains can run. This means that the departures are released for sale with significantly shorter notice than usual, sometimes only a few weeks before departure. We are really sorry about that. We release departures continuously as soon as we receive notification from the Swedish Transport Administration.
I hope this helps.
Don't use Omio, use www.sj.se to look for schedules and buy your tickets.
You don't mention when in August you plan to travel but until the 20th there is maintenance on the line between Stockholm and Oslo so it is closed. That means the direct trains are reduced to two daily that take a bit of a detour through Bergslagen. Hence it might be a bit faster to travel via Gothenburg if the connections there match up. And Gothenburg is not a bad place for a stop along the way.