I couldn't really find anything similar posted so I'll describe my situation. I have a 2009 Impreza WRX, right about 9.5k miles. It has always ran very well with no issues so far and I just got it serviced/oil changed.
The problem I think started from either accidentally putting in a lower octane fuel or fuel that wasn't premium as it said. I say this because after I filled it, the first 1/4 tank was fine, then I was cruising on the highway and it started reving up the engine. Basically, it feels very week and if I don't coax it along it will rev really high without actually speeding up. It also feels like the turbo isn't doing anything at all once I get into the rev range it normally kicks on.
I am planning on going to the dealership tomorrow but wanted to see if anyone has experience with this.