automatic tranmission

Under normal, everyday driving, in town or freeway, open highway, you need not be concerned with anything, simply put it in D for drive and go. Run errands, go see Grandma. The only time you need to do anything else is when you are driving up and/or down very steep grades, especially if you are heavily loaded, say 3 --250 men in the backseat, your 300lb mother-in-law in the passenger seat, and a trunk full of heavy suitcases. OR pulling a trailer. Personally I would never even consider pulling a trailer with my Corolla. Then, while going up a grade, just push the button on the side of the shifter and kick it out of Overdrive. You will increase the engine RPM's giving you a bit more power, mine has a tendency to lug just a little bit...it does not downshift when I think it should out of overdrive, it will go 65 up the mountain (I live at 5,500 elevation) at 3,000 rpm instead of about 2,200, giving me more poop to pass trucks. But I seldom approach the 'red line', that is a bad habit to have, running it at 5,500 rpm. It is not going to blow the engine however. Same thing downhill. Heavy load, don't ride the brakes, kick it out of O/D. You can even drop it in to "2" if you are going down a very long, steep grade, say, in snow at 30-40mph but that's not a everyday situation

Just so I am not misunderstood, it's better to drop a gear and let it run at 4- 5,000rpm downhill loaded for a while that it is to ride the brakes. There are situations when you may have to do both.

I drive a 2009 Corolla. It does not have a button on the shifter. How do I shift from D to 3 or 2 when the car is in motion and I feel the engine is straining? Thank you.

I Need to know when do I Use the E side of my gear shifter which is next to D . Drive and E or D E next to each other on gear shift knob and I don't know what E is used and when. I can slide to either drive or move left to E position . Not sure what it's used for. Sorry for repeating myself but I can't find any info on bus exact E button. Thank you.

Why does my Toyota matrix automatically shift to low gear going down a steep grade.its a 2009