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Joined: Aug 2003
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Newbie
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OP
Newbie
Joined: Aug 2003
Posts: 9 |
Hello:
So, I keep getting different advice from all my car-guy friends about using the overdrive feature on my '97 4-cyl. automatic Contour GL.
Since the overdrive is automatically on when I turn on the engine, should I just leave it on??? I've had the car since '98, and I do city stop&go driving 75% of the time. Normally I'll turn the overdrive off if I'm doing under 50mph and then turn it back on at 55mph or higher. I do notice a definite improvement in acceleration when the overdrive is off.
any advice??
Karin
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Joined: Dec 2002
Posts: 405
CEG\'er
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CEG\'er
Joined: Dec 2002
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From what i understand, overdirve is just a higher gear that the car goes into saving you gas. unless you need to accelerate really fast i'd keep it on.
Tony Datsenko
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Joined: Sep 2002
Posts: 231
CEG\'er
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CEG\'er
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I pretty much use it in stop and go driving during rush hour, or when I need to pass someone....thats about the extent of it though.
'04 Bright Red Ranger
FX4 ~ S/C 4X4
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Scourge of the Master Debaters
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Scourge of the Master Debaters
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Originally posted by Dark Sport:
From what i understand, overdirve is just a higher gear that the car goes into saving you gas. unless you need to accelerate really fast i'd keep it on.
Yup. O/D is 4th gear. I turn it off in cases where the computer doesn't know which gear it wants to be in, like while accelerating on a steady incline, since the constant shifting probably isn't good for the valve body. Leaving it off for extended periods of time will just cause undue wear and tear on your tranny and burn gas quicker.
Beer is my Gatorade.
Hooray Beer.
'98 "Sport" Pacific Green
'98 E0 SVT Silver Frost
Pictures
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CEG\'er
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CEG\'er
Joined: May 2000
Posts: 133 |
Originally posted by hetfield:
Originally posted by Dark Sport:
From what i understand, overdirve is just a higher gear that the car goes into saving you gas. unless you need to accelerate really fast i'd keep it on.
Yup. O/D is 4th gear. I turn it off in cases where the computer doesn't know which gear it wants to be in, like while accelerating on a steady incline, since the constant shifting probably isn't good for the valve body. Leaving it off for extended periods of time will just cause undue wear and tear on your tranny and burn gas quicker.
Actually on most, if not all automatic transmissions, when you push the O/D button it's not another gear.
Although you are changing gear ratios, the reason for the change has to do with lock or unlock torque converter.
When the TC is unlocked it will act as another gear ratio.
If you have your shifter in drive you should get 4th gear with a 4 speed auto trans regardless O/D on or off.
In that the TC is a viscous couple, its not efficient and you get better fuel economy with it locked when traveling at constant speeds.
For fast acceleration and starts from a stand still you want the TC unlocked to gain from the advantage of the extra gear ratio.
So for better fuel economy leave the O/D active.
When you want to accelerate very fast turn it off and then back on once you get to your desired cruise speed.
Anthony B. Davis
2Deep2 Silver SVT
2002 IASCA SQ Ult Ama 601+ World Champion runner up
2002 SLAP dBQ Champion 
2000 USAC SQ World Champion
2002 USACi SQ World Champion
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Joined: Jul 2002
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Scourge of the Master Debaters
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Scourge of the Master Debaters
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Originally posted by 2deep2:
Actually on most, if not all automatic transmissions, when you push the O/D button it's not another gear.
Although you are changing gear ratios, the reason for the change has to do with lock or unlock torque converter.
When the TC is unlocked it will act as another gear ratio.
If you have your shifter in drive you should get 4th gear with a 4 speed auto trans regardless O/D on or off.
In that the TC is a viscous couple, its not efficient and you get better fuel economy with it locked when traveling at constant speeds.
For fast acceleration and starts from a stand still you want the TC unlocked to gain from the advantage of the extra gear ratio.
From the Ford Technical Service Publications Manual (emphasis mine):
"The transaxle range selector lever has six positions: P,R,N,D,2,1. In addition, a transmission control switch (TCS) allows the driver to prevent a shift to fourth gear (Overdrive) and uses engine compression to help slow the vehicle (engine braking) in second and third gear."
It may not be the case on most other transmissions, but it appears to be the case on the CD4E, at least according to Ford.
Beer is my Gatorade.
Hooray Beer.
'98 "Sport" Pacific Green
'98 E0 SVT Silver Frost
Pictures
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I have no life
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I have no life
Joined: May 2002
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Pretty sure o/d is a 4th gear on our cars. Definitely shifts the same as another gear. And I believe the TC can be locked or unlocked in 4th gear depending on rpm and all.
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
CEG Dragon Run - October 13-15
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CEG\'er
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CEG\'er
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The CD4E is a four speed transaxle with a locking torque converter. TC lock up can occur in third or fourth (overdrive) gear. The OD button is interned to lock out the forth speed overdrive gear to prevent gear hunting in traffic and going up grades.
If you are driving in stop and go traffic and you can use it to keep the car from shifting in and out of OD. Just remember to click it off when you start cursing.
jeff
have you fixed your ford lately?
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Joined: Sep 2003
Posts: 95
CEG\'er
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CEG\'er
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on the mondeo models with OD all it does is extend the rev range between gears i,e rather than changing up at 3000rpm it waits till 4000rpm to get greater acceleration when over taking also the police here use it in pusuit runs
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Joined: May 2002
Posts: 21,653
I have no life
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I have no life
Joined: May 2002
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You sure you're not talking about the "sport mode" that is offered on euro trannies?
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
CEG Dragon Run - October 13-15
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