I decided to change my oil early to the Subaru 0w-20 at just shy of 3,000 miles 2 nights ago. Right now my MPG on the car computer is at over 28 MPG where typically it would be a couple of MPG lower prior to the oil change. The engine is smoother now and feels quicker to rev with the fresh oil.
I noticed on the expressway that I am able to get the instant fuel economy readout to sit at 40mpg pretty easily while cruising at 63mph now. I expect that my next mostly highway tank will return some great numbers even with the winter blend fuel and colder weather.