Maybe it's a silly question, but I know there are still some people who are a bit confused about the function of the Overdrive function. So I'm gonna ask away! I'm going back to school and my trip to and fro includes going through a mighty hill--not extremely steep but significant enough as to cause big rigs and underpowered cars to go 30mph or slower on the freeway. So, the question is, is it best to switch off OD and use only 3rd gear and max it out at around 40-55mph to get the torque? Or is it better to leave OD on the default on? I do the latter and noticed that it will stay in 3rd gear while going up the hill at around 45-50mph and 4th kicks in at 55mph once I begin to go down the hill. What do you guys do?