Hi esteemed Forum members. Manual overdrive (O/D) in my 07 has had me flummoxed ever since I bought the car over a year ago. Now I understand it is probably a locked converter situation or 1:1 ratio at which point the engine will begin to struggle when power is applied. Maybe my daily driver, an 04, 330k plus Honda Accord has spoiled me since O/D is really just a 5th gear that the gearbox runs in and out of as it needs to. I'm also very familiar with manual cars and truck gearbox's of the crash and 2 speed Eaton diff variety, so I guess I'm saying I do know how to change gears! Accordingly, an auto should be, and is, in most cases a piece of cake. Not so the S197 it seems. My current modus operandi is to run the car with O/D selected on. From a standing start the car moves up the gears until the speed allows it to gracefully drop into O/D. If I then brake say for another stop the gears drop down and we start again without O/D having to ever be deselected. The problem of course comes when running in O/D on a hill or conducting a passing maneuver both of which require the application of power. Absent minded and thinking I'm in my daily driver I increase power only to hear the engine struggle and even miss. A quick stab of the overdrive deselect button and .......blast.... the stab was too quick! A slower stab of the O/D deselect and the gearbox drops down, and I get some power just in time to clear that oncoming car in my now completely botched passing maneuver. This is kind a serious of course and I feel that maybe I'm not operating the O/D selector correctly. Yes, I know i should deselect O/D before commencing a passing maneuver, but muscle memory with my daily driver gets in the way of that sometimes. (which also explains why I occasionally hit the drivers door a couple times with my left arm during reverse selections, as I look for the gear change lever, thinking I'm in my RH drive Accord..Doh!). I know if I just ignored O/D and never selected it, the problem would go away, but engine noise and fuel consumption would increase. I do have a number of roads that I cruise control on so O/D is pleasant and less expensive running at 100km/hr or 60 mph. But, I just don't understand why it requires a manual deselection to drop down out of O/D when I need power and yet when the car slows down sufficiently to stop it doesn't? Again, I probably really don't understand what the operating parameters for the O/D are. Perhaps someone could point this hopeless case in the right direction before I spud in one day!!