first time for me to drive a car with overdrive features..so i'm not so sure what is the correct way to use it...

for those who doesnt know much about overdrive, can refer here :-
http://en.wikipedia.org/wiki/Overdrive_%28mechanics%29



despite the info shown above, i'm quite confuse on the overdrive function because :-

1) i have the wrong perception earlier that overdrive is like lower your gear from 3rd to 2nd (for auto) and like 5 gear to 4th gear (in manual). more power and higher rpm when you need to overtake any vehicle in front. in other words, if i'm driving auto, i'm using D gear and when i wanna overtake a car with more power, i'll change to 2 gear. but instead of doing that i will on the "overdrive" and it should have enough power to overtake it.

but with the explanation above in wikipedia, it seems like overdrive is to change from 3rd gear to virtual 4th gear. meaning better fuel saving and lesser rpm.

so am i wrong having my own thinking earlier?

if i am, should i keep the overdrive function ON all the time for myvi auto?

i heard from my friend frequent use of overdrive is not good for the gearbox...
abit confuse alridi...

If i am not mistaken, we should let the OverDrive always OFF so that it save FC. Then OverDrive set to ON for power wise.

overdrive is to maintain high rev...when over taking,on a windy corner,going up hill,sport drive...

haha so u guys perception are same with mine...

whereby what explained in wikipedia is the other way round.

so one question, what is the diff between "overdrive" and you manually change from D -> 2 ?

Most ppl will have that perception but actually OD means you will have an additional top gear so that the output rev is faster than the INput rev. but this produce low torque for comfort driving in high constant speed at a lower engine RPM.
Imagine a manual car with OD off is only up to 4th gear and when OD is switch to ON, you will get 5th gear.
Simple as that.
edit: typo INput

This post has been edited by spacepilot: May 8 2007, 09:19 PM

so OD on = better?

Myvi, by default OD is on. When you press the OD button, OD is switch off. Thus giving you the virtual 4th gear.

This post has been edited by nexuz: May 7 2007, 03:02 PM

.........


Now I'm getting really confuse too... OD as a virtual fifth gear in an 4 gear automatic car...


Err... I thought using higher gear on higher speed is better... which means OD on ie better??? Really confuse now...

It's default on, when u push the button it will show "O/D OFF" and your rev go higher.

So leave it ON for normal driving, OFF it if you need that extra bit of power to overtake.
I do OFF it instead of pushing to 2nd gear/brake to slow the car a little sometimes

This post has been edited by bearbear: May 7 2007, 03:01 PM

OIC... my bad...

No problem, i used to be confused by it too

LOL...

That is how it actually works arr...

Thanks for clearing stuff out bearbear...

the explanation in wiki is correct. it means when u r driving ur myvi, the overdrive is ON, thus ur 4th gear is actually an overdrive gear (or virtual gear). so when u turn OFF O/D, u won't get the 4th gear for cruising instead you will be revving your lower gear for more torque to be used in situation like hill climb and stuff like tat. Conclusions: just leave it on if you are not sumone who suka rev kau kau.

This is the correct answer.

Karmakid: Wikipedia is also correct. What u got confuse is whether O/D is on or off. If u read Wikipedia's paragraph carefully, it is referring to O/D=On for lower RPM and save fuel.

I'm not sure about old cars or cars in US, but i think most cars here is default O/D=ON. like my Kia Sephia, default O/D=ON. So it allows you to go to a higher gear, saves FC and lower RPM.

If u set it to off, it's like forcing the auto transmission to NOT USE the highest gear, thus allowing ur more power temporary to overtake, etc.

DO NOT SET YOUR OVERDRIVE OFF UNDER NORMAL CIRCUMSTANCES FOR LONG PERIOD. if you set it OFF for prolonged period, your auto tranny/engine will die faster...i think i read it somewhere...

This post has been edited by Matrix: May 7 2007, 03:24 PM

thx guys to clear up my doubts...

1 last question, what is the diff if i "turn off my overdrive for higher rpm" and "i change to 3"?

changed to 2nd gear u mean?

normally what i'll do is turn off O/D first to get abit more power, if it's not enough then shift to 2nd gear.

So i assume using O/D will save u some tear and wear on ur gearbox compare to shifting to 2nd gear?

yea yea...actually i wanna clarify if that "assumption" is correct or not...

i get a feeling that O/D off will save some tear and wear issue, compare to shifting to 2nd gear...but jst wanna confirm on that.

IMO, Shifting to gear 2 is quite useless...only useful when coming down from Genting in order to slow down ur car without excessive braking.

Last time i tried to put 2 to go up genting...useless...then i put O/D off only it performs normally. IMO, just put O/D off and let the ECU determine ur gear ratio instead of forcing it to a fix gear.

But of course, it could be my KIA behave like that...

ok ok....generally concept it's like that la....
well i think kia and myvi gearbox somehow diff in performance also...maybe i should try it out later....

Sometimes if you go up genting with OD off and don't have enough power, it might be running on 2nd gear So all depends on your right foot XD No power, just press the accelerator more loh