Not familiar at all with autos since all my Subarus were manual but here it goes..
Friend has a 2009 Outback/Legacy 2.5i auto and at highway cruise, around 120km/h, the rpms are suck at around 3000rpms. It sounds like the transmission won't shift forward the into the last gear or overdrive. Did a little research and it sounds like a fluid/filter change could help or maybe the temp sensor isn't allowing the torque converter to lock.
It doesn't help that it's also -30c right now so troubleshooting is kinda limited. Anyone experienced something similar?