On another auto forum, I was reading a post that talked about how it's good to turn overdrive off when driving locally. Is there any negative impact on a transmission when you turn O/D off? My thought is let the AT stay with O/D on and let it decide what gear to be in. I never really gave it much thought. I've only driven manuals the last 20 years. In a mountainous/hilly area or when towing I can see the need to turn it off, but not for city driving. Modern transmissions are fully computerized, so they are much smarter at deciding when to use overdrive than you or I.
This was one of the comments:
"I manually shift mine all the time, in 3rd for around-town and into 4th when running a bit faster but not quite able to open it up for full highway cruising. According to my AutoMeter trans temp guage, it does not appear to change anything at all temps-wise and I find the throttle response and smoothness to be greatly enhanced. My trans usually runs around 155 to 160 indicated unless crawling through town in hot weather with the AC on, like today, where it appeared that a movie or TV sequence was being filmed downtown Baltimore and traffic was diverted into a complete snarl. A total Charlie Foxtrot but temps still hovered around 195 to 200."
This was one of the comments:
"I manually shift mine all the time, in 3rd for around-town and into 4th when running a bit faster but not quite able to open it up for full highway cruising. According to my AutoMeter trans temp guage, it does not appear to change anything at all temps-wise and I find the throttle response and smoothness to be greatly enhanced. My trans usually runs around 155 to 160 indicated unless crawling through town in hot weather with the AC on, like today, where it appeared that a movie or TV sequence was being filmed downtown Baltimore and traffic was diverted into a complete snarl. A total Charlie Foxtrot but temps still hovered around 195 to 200."