I will agree that quality oil does not need to be dumped after reasonable track use. I say to dump it not because its bad, but that it is definitely overly thick and excessive for daily street use. Unfortunately, Subaru is not a manufacturer I deal with and in all honesty I dont know nearly as much about them as I do most other engines. I dont know what, if any changes were made to their engines when making the change to thinner oil. But in general most manufacturers did make changes. Things like coated cylinder walls rather than sleeves, tighter ring gaps, new ring\bearing materials, oil passage sizing all were part of this thin oil and reduced friction initiative. I wonder what the reliability track record looks like before\after the change. I mean EJs were never reliable. Was there any more\less bearing\rod failures when oil weight changed?