When to use overdrive on Mazda tribute 2001?

Overdrive is always on by default every time you turn on the engine, even if last time you drove you turned it off. Given that Mazda does this, I believe it is their intention to use overdrive all the time. However, there are times I would turn it off. This would be when going up and down small hills where the transmission has to constantly change gears. It has to downshift when going up hill, and upshift going down hill. To minimize how many times it has to go in and out of overdrive, I turn it off on those kind of drives. Also, when towing a heavy load, I recommend turning it off, since it is not designed for the extra load.