I made my decision - I'm making the switch next time I go to fill up! Thought it was odd that the previous owner used midgrade while both the owner's manual (which I did read, thank you ) and the inside of the gas tank door said differently, but I also didn't think is was good on the car to switch fuel types. Live & learn my friends, live & learn!

On that note, any opinion as to the details of injector cleaner (ie brand, how to use it, frequency)

Yeah, I always thought buying a car with low miles was best, but I'm learning that is not necessarily true. Bought it with only 8,000 on it this summer at 5 years old... the guy kept it in the garage with a cover on it. Body looks great, thank god, but sounds like the engine might need a bit of love.