Ned Posted August 11, 2005 Share Posted August 11, 2005 hey guys. i'm probably wrong as always but if your stupid auto has "over drive" then all it does is change at what rpm it changes gear right? so say, normally it would change at 4 thou but with over drive off (or on, not sure which is which) it will change at 2.5 thou... am i right or are the people that say "WOW!!! Over Drive!!! that means it has an extra gear!!!" right? please tell me they are wrong...! Quote Link to comment Share on other sites More sharing options...
CaMpylobacter Posted August 11, 2005 Share Posted August 11, 2005 it's an extra gear, essentially.... power/economy or sport/economy= changes shift points hold = manual stz Quote Link to comment Share on other sites More sharing options...
peteretep Posted August 11, 2005 Share Posted August 11, 2005 actually dvlrcr it would be the opposite of what you said. Normally it would changeat 2.5 but with overdrive it would hold in gear longer so it would change at 4 Quote Link to comment Share on other sites More sharing options...
SYKOV6 Posted August 11, 2005 Share Posted August 11, 2005 it all depends what sortr of car it is. eg commonwhores past 89 have a lock up torque convertor that drops the revs another 600 and will slip back out again when ya press the pedal down past 1/4. most jappas have a button on the shifter which im pretty sure does basically the same thing but manually. they normally have a 'HOLD' or 'SPORT' mode that makes them hang in gear longer . Quote Link to comment Share on other sites More sharing options...
TygerTung Posted August 11, 2005 Share Posted August 11, 2005 Overdrive essentially means you have an extra gear, an overdrive gear, making the engine turn less times than the driveshaft. Quote Link to comment Share on other sites More sharing options...
Ned Posted August 11, 2005 Author Share Posted August 11, 2005 then why would they have an extra gear caller over drive and not just have a 5 spd box? why would you want to have a button that lets you have an extra gear? why not have all the gears within reach right away? Quote Link to comment Share on other sites More sharing options...
Guest jomojojo Posted August 11, 2005 Share Posted August 11, 2005 Most often overdrive is another gear but one geared for economy and smoothness. In most autos when you completely lift off the throttlemomentarily instead of removing drive completely it will change to a higher gear 4/5 to smooth out the transition and rule out engine braking. The overdrive button enables/ disables this gear and therefore can affect fuel economy, and to some degree throttle response ( by increasing the time it takes to get positive drive to the wheels as the auto is busy changing down gears). All transmissions are different so just experiment with yours try turning it on/off at high/low speeds, monitoring shift points with it on/off. In my experience sports/economy buttons effect shift points only not control of the gearing. In short... Performance : Sports mode/Hold, Overdrive off Economy: Economy mode, Overdrive on After all its your car ... experiment,play,tinker !!! Quote Link to comment Share on other sites More sharing options...
fuel Posted August 11, 2005 Share Posted August 11, 2005 Yep Overdrive is effectively a high gear, much like 5th in a manual gearbox. Overdrive is not a good thing to have switched on when driving around town either, as it's like driving in 5th gear in a manual at say 50k.. it just puts too much load on the engine. Most jappas from the mid 80s have a power/economy setting too, which just alters the shift points. The shift points are usually determined by load rather than just revs. Quote Link to comment Share on other sites More sharing options...
Guest jomojojo Posted August 11, 2005 Share Posted August 11, 2005 Overdrive is not a good thing to have switched on when driving around town either, as it's like driving in 5th gear in a manual at say 50k.. it just puts too much load on the engine. Yes, but minimally as the trans, if working properly will only shift to overdrive under throttle lift off or veryvery light acceleration, generally though i have found that most start shifting down as soon as the accelerator is depressed again no matter how slight. Quote Link to comment Share on other sites More sharing options...
Ned Posted August 11, 2005 Author Share Posted August 11, 2005 but just getting back to my point. say you have a normal auto box and a over drive capable box. same box. one just has over drive right. does that mean that the box with over drive has 1 more gear then the normal box? so say 4 for normal and 5 for over drive? or does the normal box ride out the gears and the over drive shift earlier to not go up in revs too much. also, that 50k an hour thing, bull shit (sorry). my parents have their car on over drive 24/7 (and no i'm not mistaking it for power and economic because thats a diferent button, always on eco 2) Quote Link to comment Share on other sites More sharing options...
Guest jomojojo Posted August 11, 2005 Share Posted August 11, 2005 lol dvlcr i was trying to be nice about it but yeh the damage/increased load is SO minimal that it really comes down to how you wish your transmission to act. The way overdrive generally works (not to sure) is that it isnt classed as an extra gear because it does not have the associated clutch packs etc I think its in some way linked to the torque convertor's transmission of drive. Im just making educated guesses tho so dont take it to heart Quote Link to comment Share on other sites More sharing options...
Ned Posted August 11, 2005 Author Share Posted August 11, 2005 sweet as i just really want to be right here Quote Link to comment Share on other sites More sharing options...
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