I'm not sure about doing it without using premium fuel, because IMO, it isn't cost effective to get a chip that will JUST improve your shifts. If you were to increase performance and use a mid-grade fuel, then it would probably be worth it, but at $200+ for a decent chip, it's probably pointless.
I don'e even mind where the car shifts so much as how it shifts. I know this is not a race car, but the shifts take too long. The only other car I have that is an auto is a mustang with a built automatic. It chirps the 1-2 shift no matter what the throttle position and sometimes 2-3 under full throttle, I don't want it that drastic, but just a little better.