This weekend My son and I changed our 06 Accord too Mobil1 10W30 Syn and we noticed a huge difference in the starting, ( started after 1.5 turns instead of 4 ) and how well the engine ran, and it didnt shift too fast into a lower gear so fast when going uphill. My wife drove it to work today and she called me back telling me how much smoother it ran.
By the way, how come it does shift to a lower gear when going up a hill at 55?? Is this normal!?
CR

 

Glad you like your oil change performance. The transmission downshift is dependent on the engine load. The downshift depends on the vehicle speed and grade that you are climbing. All of our vehicles have downshifted on a steep grade and our Honda is no exception.