You can do whatever you want with OD...its not gonna me a difference. The reason you were close to 3k RPM is because you were in 2nd gear, and a little over 2k your in 3rd.

Its not bad for the engine at all...

 

I believe its easier on the transmission when ur doing stop n go city driving with it 'off', and maybe not an increase in gas milage, but getting my full potential, in response to your quote.

 

easier on the tranny, so it doesn't have to shift into o/d for a second or whatever in town, correct?

 

I always shut o/d off unless I can get to 55 and stay there. You're tranny will thank you if you do this.

 

it is ok to manually shift out of OD
into 3rd gear with a locked torque converter clutch
prior to a hill
where you suspect the auto trans will downshift

the slight change you see in rpm is due to the torque converter clutch locking up quicker
when you manually shift down while still on flat ground

clutch wear wise
it is probably slightly better to downshift into locked up 3rd gear
at low engine torque when still on flat/downhill highway
rather than waiting for the trans to do an automatic shift at much higher engine torque
in the middle of the hill climb

there might also be a slight MPG gain
because by manually shifting beforehand the torque converter does not slip for as long a time as it will if the middle of the hill

 

I'm with everyone else, for normal city driving well actually anything under a consistant 55MPH i turn the overdrive off. It keeps so much wear and tear off your tranny. Even if you have a little less fuel ecomony it will be worth it in the long run if you don't need to replace/rebuild the tranny as often right? We all know them are not cheap!

 

Man you guys are great. Thanks a lot for all of the information. I'm just going to start leaving OD off since I mostly do in town driving. My longer trips whereI can go 55-60 I'll leave OD on, but for the most part I think I'll benefit if I leave it off. It's much more responsive that way, and the exhaust sounds better when coasting when OD is offand if it saves me on the stress on the tranny then that would be great. I really don't want to have to replace/rebuild one of those any time soon. Thanks again guys.

 

Don't be afraid of your transmission. They were made to shift. You can go in and out of OD all you want. Ditto for downshifting, i.e. up or down hills...won't hurt a thing.

Remember, you have eyes. You can see whats coming and can anticipate conditions more so than OD or cruise etc. They only RESPOND after the fact.

 

Very good point. I guess the main reason I asked is because there are so many people who have these trannies to go out and I just want to make mine last as long as possible, and not do anything that could tear it up. I think, after all of this info I've been given, that it would probably help if I manually shift it. Like you said, since it's going to shift anyway, I know when to before it is forced to.

 

You'd be better served adding a tranny fluid cooler than worrying about OD on/off shifting.

Overheating's your main enemy, not clutch wear.