After I replaced the trans on my daughters car ( TR ) 4 cylinder I was told buy the wreckers that I got the trans from, That you should not leave the overdrive on. You should only put it on when doing 60 klm or more, and when you are slowing back down to stop you should turn it off.

What does the group think on this.

I leave on my overdrive have no ill effects yet, but magna buff says the say thing as the wreckers told you. If you look up your car instruction manual it says to leave overdrive on and only turn it off when going up a hill or when over taking. Overdrive is a fourth gear helps the engine to rev lower thus improve fuel millage :)

overdrive actually only engages when you are doing over I think it is 60 anyway, give or take 10 Ks

i personally consider this one of those myths that go around its very common but i dont see the point


why would they design an automatic with a manual button you had to use all the time :P

Overdrive is meant to be turned on above 70kph. And turned off under 70kph.

Overdrive is meant to be turned on above 70kph. And turned off under 70kph.

Why? explain to me the point. It will drive perfectly happy at 60Ks in overdrive.

My understanding is that its to hep with power when going up hills, or when towing.

My understanding is that its to hep with power when going up hills, or when towing.
It lowers the rev's to improve economy. At low speeds its just putting unnecessary strain on the gearbox I guess? Not really sure, it's always been turned on in our TR though, right from new, no issues related to that at all yet...*touch wood*

It lowers the rev's to improve economy. At low speeds its just putting unnecessary strain on the gearbox I guess? Not really sure, it's always been turned on in our TR though, right from new, no issues related to that at all yet...*touch wood*

Without being a smartass here, I agree 100%.
I've found on the Diamante, although a much different motor, uses the same gearbo, with O/D on it engages at around 40kph and is very sluggish everywhere.
Solution found! leaving PWR (Power) mode on is just sensational. Makes it feel like a much more lively gearbox. Holds 2nd for more then half a second, holds third till about 55kph and then engages 4th.

Just remember that at one RPM (Says 2000) you have a heap of different fuel cells (load) for that one RPM. So if the engine is under strain trying to pull the car from 2000RPM you may think its being fuel efficient when in reality up a small incline or trying to pass a car, your putting it under heaps of load meaning its gotta inject way more fuel.

Looking at my fuel map now, and it actually uses heaps more fuel labouring at low RPM compared to a fractionally higher RPM

So basically - I leave O/D on, but with PWR mode on aswell, and actually makes the slushbox 4sp feel alright.

;1327728']Without being a smartass here, I agree 100%.
I've found on the Diamante, although a much different motor, uses the same gearbo, with O/D on it engages at around 40kph and is very sluggish everywhere.
Solution found! leaving PWR (Power) mode on is just sensational. Makes it feel like a much more lively gearbox. Holds 2nd for more then half a second, holds third till about 55kph and then engages 4th.

Just remember that at one RPM (Says 2000) you have a heap of different fuel cells (load) for that one RPM. So if the engine is under strain trying to pull the car from 2000RPM you may think its being fuel efficient when in reality up a small incline or trying to pass a car, your putting it under heaps of load meaning its gotta inject way more fuel.

Looking at my fuel map now, and it actually uses heaps more fuel labouring at low RPM compared to a fractionally higher RPM

So basically - I leave O/D on, but with PWR mode on aswell, and actually makes the slushbox 4sp feel alright.


Funny you mention that FUEL LOADING issue Tuffy as I have found the 380 Auto will shift to 5th gear ASAP
The engine then uses its available torque to over come inclines rather than shifting into a lower gear and the ECON climbs

THANK GOD FOR TIPPY MODE!!

Funny you mention that FUEL LOADING issue Tuffy as I have found the 380 Auto will shift to 5th gear ASAP
The engine then uses its available torque to over come inclines rather than shifting into a lower gear and the ECON climbs

THANK GOD FOR TIPPY MODE!!

Well my 1991 Car doesn't have a 5 speed "sports gearbox" so I need use what I have!

InvecsIII conversion on the cards then tuffy

InvecsIII conversion on the cards then tuffy

lol! I have other things on the cards for this car mate but I will keep them to myself! No more "conversions" for me mate.....had my time....

on the 4 cyl auto

if you leave the overdrive on all the time

you wear out the end clutch

and its a $200 + repair
the amount saved in petrol is not = to $200 repair

Hi TUFFTR do you have a couple of cars?? I might try your set up with the power button on and over drive on.

( The trans in my daughters car ) The second gear band was broken. I didn't feel confident enough to try and pull it to pieces and fix it,, so I just brought a second hand trans. Does anyone know much about what’s involved in replacing a broken band ( Just for future REF ) If I seen it done I probably could do it BUT reading the work shop manual forget it.

HOPE THAT MAKES SENSE

Hi TUFFTR do you have a couple of cars?? I might try your set up with the power button on and over drive on.

( The trans in my daughters car ) The second gear band was broken. I didn't feel confident enough to try and pull it to pieces and fix it,, so I just brought a second hand trans. Does anyone know much about what’s involved in replacing a broken band ( Just for future REF ) If I seen it done I probably could do it BUT reading the work shop manual forget it.

HOPE THAT MAKES SENSE

I do indeed mate :) Little things I can tell
Both O/D on
PWR Off
Changes gear every 10km/h or so getting into 4th about 40km/h
PWR on
Changes gear every 20km/h or so into 2nd about 20km/h, 3rd about 40km/h and pulls nicely all the way up to around 60km/h
So I am leaving PWR on atm as it just feels beautiful to drive ad alot less sluggish. Of course when you plant it it's another story but down low, like every other 2nd gen, a bit sluggish around town

Overdrive is like the 5 gear on a manual, you only go into 5th gear when your out on the highway, so you only go into overdrive when your on the highway when crusing, and out of O/D when your going up or down step hills, its not rocket science, go out of O/D when you need more power without too much excelleration and when you need to slow down going down hills which slows the car just like you would go out of 5 gear in a manual going down hills.

Overdrive is like the 5 gear on a manual, you only go into 5th gear when your out on the highway, so you only go into overdrive when your on the highway when crusing, and out of O/D when your going up or down step hills, its not rocket science, go out of O/D when you need more power without too much excelleration and when you need to slow down going down hills which slows the car just like you would go out of 5 gear in a manual going down hills.

Yeah but 5 gear ratio's are different to 4 gear ratio's. But hey if you want to sit on 3000RPM @ 80km/h everywhere in 3rd gear go right ahead.

if you leave it on PWR mode it'll do everything for you as it kicks down earlier, changes up higher and revs out alot more

;1328022']Yeah but 5 gear ratio's are different to 4 gear ratio's. But hey if you want to sit on 3000RPM @ 80km/h everywhere in 3rd gear go right ahead.

if you leave it on PWR mode it'll do everything for you as it kicks down earlier, changes up higher and revs out alot more


If I'm doing 80K's an hour I would be in O/D, i'm talking about doing 40-60 k's around town with O/D off, not sure what your going on about.

If I'm doing 80K's an hour I would be in O/D, i'm talking about doing 40-60 k's around town with O/D off, not sure what your going on about.
I'll show you :)

Overdrive is like the 5 gear on a manual, you only go into 5th gear when your out on the highway, so you only go into overdrive when your on the highway when crusing, and out of O/D when your going up or down step hills, its not rocket science, go out of O/D when you need more power without too much excelleration and when you need to slow down going down hills which slows the car just like you would go out of 5 gear in a manual going down hills.

You say 40-60k's now, but just there you said on the highway, never seen a highway myself that's 40-60k's.
or just leave PWR mode on and it does it all for you....

PWR mode on and O/D on for me, worked a charm, oh and I used to do 100kmp/h in third... limp home mode and a car noob >.< haha my mechanics course quickly set me straight there, how about i ask you this, why would a car manufactuer give you something standard, thats bad for your car?