"S" button in Automatic Cars ?!


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just tried to drive my friend Opel Vectra 2000cc automatic car , and i noticed a buttom 0n the gear called "S" and when pressing it the car jump 2~3 x10000 RPM, its just like kicking off with car or pressing the accelartion peddle to its max...its very good feature really as it increase the power alot of the car but they write in the manual its sucks alot of gas...

the thing i wanna know , and i with my friend cant find ,

is whats the button exactly this option do in the motor so it get this extra power??

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Eh ... definitly NOT overdrive. Overdrive lowers the speed of the engine, it doesn't raise it.

Sounds like sport mode to me.

It doesn't do anything to the motor, it simply changes the shift points of the automatic tranny. It causes the the tranny to go into the next lower gear, likely moving the engine RPM into its powerband AND lowering the gear ratios, making the vehicle easier to move, which results in the power increase that you perceive.

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Eh ... definitly NOT overdrive.  Overdrive lowers the speed of the engine, it doesn't raise it.

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What he means is that some transmissions come with a button on the shifter (or elsewhere) that disables overdrive, which would keep the engine revs higher.

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S = sporty driving mode.  The car will shift sooner to allow greater control over accelleration

E = economy, shifts later to conserve gas.

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Isn't it reverse? The later you shift, the more gas you waste?

Also, can someone explain to me what overdrive is? I never get what it means and what it actually does.

dL

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sound slike the overdrive button, though why it's labeled S I don't know...

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honda's here are labled S.. except for new ones, it just says overdrive.

S = sporty driving mode.  The car will shift sooner to allow greater control over accelleration

E = economy, shifts later to conserve gas.

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yep.

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Old feature in Opel (Vauxhal here in the UK) cars. Sports mode, pumps more fuel through the system, generally boosts the performance via slightly different gear ratios. Really useful for quicker acceleration but not something you want to be using continuously due to poor fuel economy. My father drove automatic Vauxhal Cavaliers, then Vectras in the early-mid 90's and they all had this feature.

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Overdrive is an additional gear (normally on a manual gearbox) that can be engaged by a switch, they were common on cars in the 50's and 60's, which only had 2, 3 or 4 speed gearboxes.

They normally only operate on the higher gears, and in effect provide an extra gear for each gear they can operate in.

They sit between the normal gearbox and the output shaft and lower the revs for a given speed.

Now that cars have five or six speed gearboxes as standard, with the top gear being above the 1:1 ratio, they are no longer that common (if they are produced at all...)

'S' in an auto box normally means sport mode, which means that it will hang on to each gear longer before changing up, will kick / change down earlier and will make the car respond more sportily at the sacrifice of fuel economy and smoothness.

A lot of modern autos have some form of learning facility that means the car learns how you drive and adapts the gear changes to that, which largely removes the need for the different modes in auto boxes.

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S = sporty driving mode.  The car will shift sooner to allow greater control over accelleration

E = economy, shifts later to conserve gas.

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Wrong way round. Economy shifts earlier to reduce fuel usage by avoiding the power band, sports holds on to gears longer to get higher into the power band.

Old feature in Opel (Vauxhal here in the UK) cars. Sports mode, pumps more fuel through the system, generally boosts the performance via slightly different gear ratios. Really useful for quicker acceleration but not something you want to be using continuously due to poor fuel economy. My father drove automatic Vauxhal Cavaliers, then Vectras in the early-mid 90's and they all had this feature.

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Can't change gear ratios unless it's a CVT type gearbox, which Cavaliers and Vectras never had. I doubt it changed the fuel ratio either.

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S = sporty driving mode.  The car will shift sooner to allow greater control over accelleration

E = economy, shifts later to conserve gas.

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Other way around, actually.

Higher RPM = More power and more gas used. FOO!

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agreed with pilsbury on the overdrive, my 4 speed mgb roadster has an 'extra' overdrive for a bit of extra kick at high speeds.

definatley a GM thing my old vauxhall sintra (chevy venture) had a 4 speed auto box coupled to a 3.0 v6. the change up was usually 3000rpm but with s (or sport) it'd change up about 6-7,000 rpm. i.e. much more acceleration.

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Now that cars have five or six speed gearboxes as standard, with the top gear being above the 1:1 ratio, they are no longer that common (if they are produced at all...)

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Not sure where you're getting this "five or six speed gearboxes as standard", but most cars that have an automatic have 4 and overdrive.

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Could it be the kickdown thing, cant remember the proper name that automatics have. I know most when you push the accelerator right down it goes down to the lower gear to give the most acceleration. I think its called kickdown or something.

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Kickdown is as you say when you put your foot down it shifts down a gear to get the revs in the powerband. As for overdrive i always thought it was just on manual boxes where you the final gear is not meant for maximum speed but just for economy driving. The gear below it usually gives a higher top speed. PS i drive the most basic automatic - a mini 1000 auto!

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Kickdown is as you say when you put your foot down it shifts down a gear to get the revs in the powerband. As for overdrive i always thought it was just on manual boxes where you the final gear is not meant for maximum speed but just for economy driving. The gear below it usually gives a higher top speed. PS i drive the most basic automatic - a mini 1000 auto!

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Overdrive is any gear that has a ratio lower than 1:1 (get it, over-drive?). For example, first gear has a ratio near 4:1. This means that when you're out on the freeway, instead of asking the engine to spin at 3,000RPM for 60MPH/100KPH, you can go into overdrive and it will lower the engine speed and save gas. Overdrive can be found on automatic or manual transmissions.

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Then how thats thing grab this more power exaclty??? , i am little confused with all this answers...

and wondering if its just kick the gear to the next lower one , then whats the difference between it and just getting the end of ur accleration peddle..its just do the same...

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Yeah, as so many people have replied, it's the reverse of what cswadner said. S is a sport mode that makes the engine run out the gears further which provides more acceleration. Certain manufacturers do different things with sport modes as said before, a richer fuel to air mixture, faster shifts, etc, but in general, sport mode just makes the car quicker and more responsive at the expense of gas milage.

Then how thats thing grab this more power exaclty??? , i am little confused with all this answers..

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At higher RPMs, the engine can accelerate faster, I could get into physics to explain, but that's just how engines work. However in that higher RPM range, you have to use more gas to keep the engine running that fast so normally automatic engines will shift low so they don't waste gas.

Edited by Betaz
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