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Joeye27
10-23-2007, 01:47 AM
So what do you guys prefer to do leave overdrive on all the time??? or leave it off???

im guessing for stop and go traffic and in the city leave it off and for long highway trips at the same speed over 60 or going up hill,and pulling to leave it on???

the little overdrive button since i bought the car has alwasy been pushed in leaving overdrive engaged???

when its pushed out the little light says O/D off...

well i never wanted anything to happen to my Celi so i just left it the way it was but Im asking these questions because on the high way when i push the O/D button so it says O/D off on the dash, it seems the car pulls a little more and the revs are much higher???
im assumming this is normal??? also i drove it today with it off and the car seemed alot more faster???
and when its on im guessing (4th gear)the rpms are really low?? normal???

I tryed searching for answers for my questions but get mixed answers on weather to leave it on all the time or you shouldnt.

just want to find out whats best for the Celica

Thanks

celicaGT90_05
10-23-2007, 02:09 AM
overdrive is just another gear ratio in the transmission used for gas saving, so when you turn it off, the transmission downshifts which is why you get more power and why the engine is in higher RPM's. When I need to go around someone or goin up a hill and its doggin O/D I turn it off. It wont hurt anything to switch it off. I doubt you've done it, but if you drop your drive selector to 1, that means it will only go in 1st gear, if you switch it to 2, it will only shift up to 2nd gear, if you leave O/D off, it will only go up through 3rd gear, if you turn it on then you basically get a 4th gear and the final drop of RPM's is the torque convertor clutch

celica91gts
10-23-2007, 02:11 AM
when i get tired of driving manual i take my old car out and its an auto with over drive. i noticed all that too. when i have overdrive on the rpms are a lot lower so i just keep it on for better fuel mileage. when i turn it off my dash also says od off and its annoying and so i just leave it on. as for is it better on or off. i dont actually know. sorry man

celicaGT90_05
10-23-2007, 02:14 AM
^^ refer to what I just posted

MarcusM2007
10-23-2007, 03:26 AM
lol When I first got my car I called it the "turbo button" now I understand it and its pretty useful when you need to push the limits.

Fuelish
10-23-2007, 07:36 PM
I generally only turn the o/d off when I want some gentle engine braking down mild hills. Most usually it's on (for fuel economy), and if I want to delay it's onset (like around town driving or some "spirited" backroad/mountainroad driving) and for (somewhat) more fun driving, I'll use the ECT button (dunno if that's on all slushbox Celis or just the 5sfe equipped). Delays shift points of all gears to higher rpm, o/d usually kicks in at no lower than 40 mph, as opposed to around 30-ish when ETC is off and engine is under no particular load on a flat road. Of course, gas mileage suffers when using the ETC, more than I thought it would, at least in my car .....

Joeye27
10-23-2007, 09:16 PM
any other help will be greatly apprecited, thanks for all he info so far...

juggernaut
10-23-2007, 09:32 PM
overdrive is a gear ratio lower than 1.00. with the celicas, peak power is made in the 5000 rpm range, so with overdrive off, your revs are higher (because of a higher gear ratio) so your revs are closer to the powerband. thats why it seems a lot faster with overdrive off. if i was you, i'd just leave it on. keep the dash light off, get beter fuel mileage, and when you want to race or just boot around, turn it off. it doesnt hurt anything turning it on or off while driving because you have a torque converter, but do NOT flip it on and off repetedly as fast as you can. all i can say is that it screws crap up inside the trans

Hookecho
10-23-2007, 09:56 PM
can someone tell me what is my underdrive button for?

Newbster
10-23-2007, 10:11 PM
What is this ETC button? Where is it, I've never seen it in my car.

celicaGT90_05
10-23-2007, 10:34 PM
overdrive is a gear ratio lower than 1.00. with the celicas, peak power is made in the 5000 rpm range, so with overdrive off, your revs are higher (because of a higher gear ratio) so your revs are closer to the powerband. thats why it seems a lot faster with overdrive off. if i was you, i'd just leave it on. keep the dash light off, get beter fuel mileage, and when you want to race or just boot around, turn it off. it doesnt hurt anything turning it on or off while driving because you have a torque converter, but do NOT flip it on and off repetedly as fast as you can. all i can say is that it screws crap up inside the trans

But I wanted to fry the circuit :( haha but yeah I forgot about it being lower than 1. On most cars, 4th gear is a direct ratio of 1 (motor speed in corolation with the drive output speeds) and instead of having a special gear set of it, usually just lock the input shaft of the transmission to the output shaft. Overdrive is mearly a gas saving gear

Hookecho
10-23-2007, 10:39 PM
What is this ETC button? Where is it, I've never seen it in my car.

ECT...changes the shift points of the auto tranny so that it shifts out at higher rpms. your car didn't come with it. mine did. :wiggle:

Cavanagh
10-24-2007, 12:31 AM
any other help will be greatly apprecited, thanks for all he info so far...
What else more do you need to know? Just think of it as your 4th gear. Keep it in for better fuel economy.