What exactly does the "Overdrive-off" do in my car?

[acemcmac]

I have this neat little button called "Overdrive-off" on my automatic transmission, but I've never been able to find a clear explanation of EXACTLY what it does and what the drawbacks/benefits of it are... its not in my manual. could someone enlighten me?

 

[Crazymofo]

It stops the trans from shifting to overdrive...

 

[MercenaryForHire]

Turning off overdrive removes the top gear from your automatic transmission. Useful if you need to go up a hill, pass, or otherwise drop down to 3rd (or 4th, if you have a 5-gear auto) - not so useful for general driving.

- M4H

 

[Mr N8]

I turn overdrive off when I'm pulling my camper trailer. Extends your gears, and doesn't allow you to use the top one. (At least that's what my ears tell me)

 

[iwearnosox]

It keeps your car on the road. Turn it off and drive off a cliff, it really works!

 

[Zee]

it's too keep your RPM low to moderate. It's for gas saving purpose. do a search, i think there's a detailed explanation somewhere.

 

[Quixfire]

Originally posted by: Crazymofo
It stops the trans from shifting to overdrive...

 

[CraigRT]

car revs higher also... you get more power on tap
overdrive saves gas though

 

[dmurray14]

Originally posted by: Zeero
it's too keep your RPM low to moderate. It's for gas saving purpose. do a search, i think there's a detailed explanation somewhere.

Uhm, I would think it does the opposite. By not allowing the shift to the final gear, the engine will be working harder to go the same speed.

Edit: Maybe you were talking about overdrive, and not the "overdrive off" button?

 

[acemcmac]

I tried googling it but i kept coming up with blanks... thanks for the info...

makes me wonder wtf its doing on a mustang V6 then if its something you'd normally use for towing...

 

[JulesMaximus]

Most cars/trucks with an overdrive gear have the ability to turn off overdrive (either with a switch or by moving the shift lever to D or 3). Sometimes when going up long hills or driving with the vehicle loaded the transmission will hunt between gears excessively which is very hard on the transmission. Turning off overdrive will keep it from doing this but your engine revs will increase as will fuel consumption.

That is why your vehicle has an overdrive off switch.

 

[JulesMaximus]

Read your manual. I'm sure it covers it in there.

 

[TheKub]

Overdrive = regular driving
!=Overdrive = towing

 

[Pepsi90919]

Originally posted by: Zeero
it's too keep your RPM low to moderate. It's for gas saving purpose. do a search, i think there's a detailed explanation somewhere.

if by "RPM low" you mean "RPM high" and by "gas saving" you mean "gas wasting" then you're correct.

 

[wasssup]

Originally posted by: MogulMonster
I turn overdrive off when I'm pulling my camper trailer. Extends your gears, and doesn't allow you to use the top one. (At least that's what my ears tell me)

i don't think it "extends your gears" ... i mean, yeah, it'll stay in third gear on a 4 speed auto, but i don't think the gear ratios change.

 

[sygyzy]

I think of it as a TURBO BOOST for going up hills.

 

[ndee]

Originally posted by: Pepsi90919

Originally posted by: Zeero
it's too keep your RPM low to moderate. It's for gas saving purpose. do a search, i think there's a detailed explanation somewhere.

if by "RPM low" you mean "RPM high" and by "gas saving" you mean "gas wasting" then you're correct.

lol.


On our Carina, it prevents the car from shifting to 4th gear(last gear)

 

[eakers]

i was told to use it when going up a big hill or merging on the hiway

 

[MercenaryForHire]

Originally posted by: sygyzy
I think of it as a TURBO BOOST for going up hills.

OMG, it's teh NAWZ!!!!!1!!1!!one!1!1eleven

- M4H

 

[Sundog]

Originally posted by: wasssup

Originally posted by: MogulMonster
I turn overdrive off when I'm pulling my camper trailer. Extends your gears, and doesn't allow you to use the top one. (At least that's what my ears tell me)

i don't think it "extends your gears" ... i mean, yeah, it'll stay in third gear on a 4 speed auto, but i don't think the gear ratios change.

Don't you think that by saying "extending your gears" he may be implying that the shift points may change thus keeping you in each gear to a higher RPM before shifting.

 

[fastz28]

OD = highest numerical gear in your transmission. e.g. 5th gear in your 5-speed.

Leave it on = low rpm, high mpg, good for highway cruising
Leave it off = high rpm, low mpg, good for towing, hills so your tranx doesn't hunt between gears.

 

[Tret]

Originally posted by: fastz28
OD = highest numerical gear in your transmission. e.g. 5th gear in your 5-speed.

Leave it on = low rpm, high mpg, good for highway cruising
Leave it off = high rpm, low mpg, good for towing, hills so your tranx doesn't hunt between gears.

 

[m2kewl]

get a manual, problem solved!

hey! someone had to say it!

 

[Aftermath]

OverDrive = any gear ratio smaller than 1:1.
When your transmission shifts into overdrive the input from the engine is slower than the output of the transmission. It's great for highway speeds because it drops the RPM of the engine, and you maintain speed, but you lose power (which isn't necessary when you hit the cruise control on the highway anyway.) You're not supposed to use overdrive when towing anything though, and it's advised against using in town where the tranny will shift in/out of overdrive, so that's why there is an option to turn it off. On other (or maybe older, I haven't driven a new auto in years), on the gear shift you had O (with a D in it) for Overdrive, and just D for your standard gears (keeping the car from shifting into OD.)


I know I know, I'm a few hours late on this thread.

 

[Cyberian]

Originally posted by: Zeero
it's too keep your RPM low to moderate. It's for gas saving purpose. do a search, i think there's a detailed explanation somewhere.

God, I love this place!!

Why do people who have absolutely no idea WTF they are talking about insist on making asses out of themselves??