Originally Posted by Unabomber
You are worrying too much. Stop thinking that conventional motor oil shot Kennedy from the grassy knoll. Change it back to synthetic tomorrow, next oil change, or never as you see fit and go to another place for oil changes. Nice of you to ask, but you've already been given your answer, so accept it rather than to deflect it.
The answers that were given were to "change my own oil", "tests are $5,000", and that "Synthetic is not required". I acknowledged all answers and challenged only the one that is directly below this reply (not knowing that there was in fact a turbo model Forester). IMO people learn by information and I was given that information challenged the opinion and got more information to which I now understand.
Originally Posted by bluesubie
The Forester is not a completely different car and yes they have a turbo model. Every note that SoA puts out about synthetic is different than the last. Note that your manual says that synthetic is required for optimum engine performance, not that it's "required" full stop.
And who's definition of synthetic are they using? Not the API's because they don't have one. And replenishment with 5W-40 conventional is allowed? There's NO such thing! In an email newsletter, SoA said that the new Impreza requires 0W-30 conventional. No such thing as that either and the Impreza specs 0W-20 synthetic. The Outback's manual says synthetic may be used but you have to stick with it if you switch to it. 1980's logic.
I'm not suggesting that you run only conventional, but a 3k mile run isn't going to hurt anything.
My apologies I don't know to much about Subarus other vehicle lineup. Thank you for your input...