I just bought a '96 Toyota T100 (automatic trans). When I asked the former owner when to use overdrive, he gave me a long convoluted answer which I don’t remember (he had it turned off when I was doing the test drive). I looked up overdrive in the manual and it tells me where the button is, but nothing else. I’ve read opinions online ranging from “use it only on highway driving” to “use it all the time”.
This will be for you to experiment with as you learn your truck.
Generaly you will not want the transmission to be shifting in-out-in-out-in-out of drive/overdrive.
( don’t know the T100 ) but I notice this in my truck about 40-45 on a stretch of in town boulevard where continualy needing to make minor speed adjustments in traffic is quite confusing to the transmission.
So, in town I switch off the o/d.
As I see a nice long drive ahead of me at sustained 45mph and more, I switch on the o/d for better mpg.
I had a 96 T100 for 6 years and the only time I ever turned off the OD was when going down a long hill so I wouldn’t need to use the brakes as much as I would with it on.
I now have an 02 Tundra and do the same thing. My transmission has never acted confused… : ).
Use it all the time, except-
- When you’re going down hill and want engine braking to help keep your speed in check.
- When towing
- If you find the transmission ‘hunting’ back and forth between gears.