i know this has been discussed before but...everyone said the overdrive on the auto is automatically on overdrive(as in normal driving)...my dealer told me that its on overdrive when its on D...and he said its normal when its on 3...can anyone confirm? thanks

 

That is correct

Erin

 

I believe overdrive is nothing more than 4th gear, a very long ratio'd gear which allows low RPMs to run at highway speeds.

 

I'm kind of confused about the overdrive thing. Can someone explain. Also why do they have the different gear choices other than D?

 

Overdrive just means the car is able to use all of its available gears. If it is on 3 it can only use 3 of it's gears, 2 only 2 of its gears, etc...

Some cars have an over drive button which just stops the car from being able to use its highest gear, usually when you have to accelerate faster for some reason you would want to turn off overdrive.

 

I know in my current car (1996 Corsica) When I have it set in overdrive the car can use all 4 gears & the torque converter can lock up in 3rd & 4th gear to help better my milage. When in normal drive the car still goes through all 4 gears just that the torque converter does not lock up so I dont get as good of milage. Im not sure how it works in the tC but I would think something like this.

 

i cant remember what the tc has...but how come you can shift to like 2 3 or 4 in an automatic?

 

Any tC owners who question this READ YOUR MANUAL!!!!! Its all explained in the manual.
LOL

Erin

 

Most autos either have it where you can selct 2, 3, D or like a 1, L, D etc.. This is for those who need to keep the auto in a certain gear because they are brave enough to tow something. Other then that I cant think of much of a use. With my current car I nail it down to drive if I need to pass some one, if I just nail the gas takes the computer about 10sec to notice I want to go faster.

 

Sometimes if you have a the car loaded with people and/or cargo and driving up mountains, you would want to put in "3" so the autodrive is not continuing going in/out of the overdrive.

Kevin

 

Or if you're driving in snow you often want to keep it in 3rd. Also downshifting to a lower gear helps slow the car down in slick conditions instead of just relying on your brakes.

 

i heard downshifting with an auto is not good for your car.... or is that shifting to 2???

 

ok, so when you put it on D, that's normal driving right??

 

usually yeah D is for normal driving.. D is where all 4 gears get used.. if you want more sporty driving.. more engine rpm's.. you can shift it to 3 and get more acceleration out of the car.. usually on ice you don't want to downshift where it causes a huge rpm increase.. as this spins the tires.. and trust me, done it on other automatics.. not a pretty thing..

 

so how bad is downshifting on an auto anyways??

 

well.. if you slammed it into L (first gear).. and you were on the highway.. bad things happen

but seriously.. going from D (4 speeds) to 3 (3 speeds) would instantly change the gearing.. and you'd have more power.. that's the downshifting people are talking about.. but you're asking if it does any damage? no. the transmission is computer controlled, it knows when to get those gears in.. i don't think you'd do any damage at all.. except seriously.. don't be doin 80 mph and then slam it into 2 or L.. you'll bounce off that rev limiter very very quickly.. doing that alot and the transmission wouldn't last..

i've done it before on many many cars.. doesn't hurt a thing to go from D to 3.. and if you're slow enough you could do 3 to 2.. but usually d to 3 works well..

hope that helps.. :D

 

SOme people claim to be an authority, but nothing has more authority than your manual. . .
If you want the easy answer, leave it in D (there should be no light saying O/D on the dash). Shifting is not harmful to your engine, assuming that you know how to shift(not going to 1st at 60mph, or excessive revs. . . other than that, shifting on an auto has no harmful effects. . . all it does is signal the ECT (electronically controlled transmission no not engage a certain gear, from highest gear down, O/D, 3,2,1). Doing it excessively or irresponsibly can hurt your car, but remember that there is no clutch to burn. . . however doing it too often (as in a means to race the engine) will burn your tranny fluid which can be replaced for about $60. If you regularly change your fluid, your engine/tranny will be fine, however failing to change burnt fluid is a BAD idea. They actually make aftermarket transmission fluid coolers for this reason. . . a smart and cheap modification to prolong your transmission life in any car under any driving circumstances.
However, I remember from my former car, an old Lexus, the ECT was not very smart, and did not properly rev match when shifting(manumatics are designed to do this and always rev match). Assisting the shift by a small throttle blip will help decrease transmission wear and smooth the sudden jerk from shifting. I'm not sure how "smart" the tC's ECT is, so I can't speak for that particular car. . . however if you have no idea whatsoever about what I'm talking about, just leave it in D, and only shift when you need it, going up or down steep hills, as the manual says. Even then, you don't REALLY need to shift it. . . it's an automatic.

 

Read the manual on what it says for max speeds to shift the auto. I dont have my manual on me atm, but I do remember that it says that 77mph is the max for 3rd. So avoid downshifting from D to 3 if you are going 77+.