"S" button in Automatic Cars ?!


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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.

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.

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Thanxx man , thats very clear and straight...

LOL at my friends , he said thats this button just open another valve in the car :x

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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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Ah true true... my old volvo had a button to engage the overdrive on the stick. 4 spd + overdrive, it was handy, it had no pickup whatsover in OD but it cruised along at 75 no problem.

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My Dad's Diesel Merc has one, C for Comfort and S for Sport. He drives it in Sport all the time, but it's automatically adapts anyway. It also has a button under the throttle that kicks down a lot harder so that when you really punch the throttle it zooms, and it does for a diesel.

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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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You are mistaking an overdrive GEAR e.g., a gear that has a ratio of higher than 1:1 with an overdrive UNIT, which I described earlier.

Lots of 6 speed boxes have 2 overdrive gears that are higher than 1:1.

Older cars used the overdrive unit as they maybe only had say 3 gears, all of which were under 1:1, so, the overdrive allowed 3rd + overdrive to be over 1:1 to allow for lower fuel usage and better crusing.

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You are mistaking an overdrive GEAR e.g., a gear that has a ratio of higher than 1:1 with an overdrive UNIT, which I described earlier.

Lots of 6 speed boxes have 2 overdrive gears that are higher than 1:1.

Older cars used the overdrive unit as they maybe only had say 3 gears, all of which were under 1:1, so, the overdrive allowed 3rd + overdrive to be over 1:1 to allow for lower fuel usage and better crusing.

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:sleep:

No.

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...)

It's wrong. Go to Nissan, Chevy, Ford, Honda... Any website you like. Pick a low end model with an automatic transmission. Let me know how many have 5/6 speed automatic gearboxes standard.

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Just because American cars are built to jurassic standards (live rear axles, four speed gearboxes and so on) doesn't change what I am saying.

Most small European cars (including Nissan, GM, Ford and Hondas) with auto options have 5 or 6 speed boxes, or a CVT gearbox (a large amount of which have some sort of set ratios to offer a manual shift).

An overdrive GEAR is totally different than an overdrive UNIT

Example of an overdrive GEAR (from a BMW 5 speed gearbox):

1st - 3.83

2nd - 2.20

3rd - 1.40

4th - 1.00

5th - 0.81 <-- This is an overdrive gear

Overdrive UNIT, confirming what I was saying (and you seem to think is wrong):

http://en.wikipedia.org/wiki/Overdrive_(mechanics)

The point of the overdrive unit was that very few cars with 3 or 4 speed gearboxes had a gear that was over 1:1...

Edited by Pilsbury
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Just because American cars are built to jurassic standards (live rear axles, four speed gearboxes and so on) doesn't change what I am saying.

Most small European cars (including Nissan, GM, Ford and Hondas) with auto options have 5 or 6 speed boxes, or a CVT gearbox (a large amount of which have some sort of set ratios to offer a manual shift).

An overdrive GEAR is totally different than an overdrive UNIT

Example of an overdrive GEAR (from a BMW 5 speed gearbox):

1st - 3.83

2nd - 2.20

3rd - 1.40

4th - 1.00

5th - 0.81 <-- This is an overdrive gear

Overdrive UNIT, confirming what I was saying (and you seem to think is wrong):

http://en.wikipedia.org/wiki/Overdrive_(mechanics)

The point of the overdrive unit was that very few cars with 3 or 4 speed gearboxes had a gear that was over 1:1...

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What in God's name does that have anything to do with what I was quoting? And you can say American cars are built to Jurassic standards (boohoo) but face it, America is the largest automobile market in the world (for now, until China takes over, if they haven't already). I don't know why you went to wikipedia to get a link when I've already stated what overdrive is. I never said that your definition of overdrive was wrong, I said (twice now, learn to read AND comprehend) that many automatic transmissions only have 4 ACTUAL gears. And thank you for furthering my point by going and getting BMW transmission ratios, because we all know BMW makes cheap cars.

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BMW make cheap cars do they?

Funny how they have such a better image than Ford, GM, and so on.

Plus they aren't stuck in the 1970's with 4 speed gearboxes, 2 valve per cylinder engines that struggle to put out more than 60bhp a litre and live rear axles.

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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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Surely you said a lot of auto cars only have four speed auto boxes?

Do you mean that a gear over 1:1 isn't a gear, because 4 + a overdrive = 5 gears.

Or do you mean a car that has a four speed box and an overdrive unit?

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BMW make cheap cars do they?

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You are really bad at picking up sarcasm. I mean REALLY bad :no:

http://saturnmpls.com/ion_quadcoupe_specs.htm

Notice "4-speed automatic"? It still has electronic/hydraulic "overdrive". There is no physical overdrive gear in these automatic transmissions. Going off and getting BMW's automatic transmission specs mean nothing, because, as you apparently missed in my previous post, BMW makes luxury cars.

Look, I'm as sorry as anybody that automatics are more prevalent in America than manuals, and I understand that manual is more prevalent in Europe, but the only way to call a 5 speed gearbox "standard" would be to count only manual transmissions (which is apparently what you're doing since you linked that wikipedia article that talks only about manual transmissions). Might work in Europe, but not in America.

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I think yall are arguing about something you agree on...or at least, I can't figure out what you're arguing about :D What are you arguing about?

From what I can tell:

-I don't really know about how many gears auto tranny's have these days, I just know its a few. My 11 year old blazer has an overdrive gear, but no physical overdrive unit. In fact, I think the only reason they tell you its an overdrive is so that they can also tell you not to use overdrive offroad.

-An overdrive is when the ratio is less than 1:1. It doesn't matter if its a separate unit from the tranny or a gear in the tranny. Often, it isn't called overdrive, but it is still less than a 1:1 ratio.

-Internet Rule #45454 Sarcasm doesn't travel over the internet.

-Pushrod V8 engines make power power per dollar than any other design. They're cheap, thats why we have them.

-There is nothing wrong with a solid rear axle IMO. If they ever EVER put independent suspension in the back of a pickup I am going to be ****ed. In cars its debateable though :D

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You are really bad at picking up the point. I mean REALLY bad :no:

Overdrive UNITS are normally only found on manual gearboxes.

BTW, BMW make what you would call a "small" car, e.g. the size of a Focus and the Saturn, and in the same sort of price range as other cars that size (which would in your terms make it a 'cheap' car, and not a luxury car). Guess what? Apart from the base 1.6 model which has a 5 speed box), all of them have SIX (yes, you read that right, 6!) forward gears. Even the autos!

So, just in case I am not understanding you, and before I lose all the will to live in trying to understand WTF you are on about...

You are saying that most American auto cars have 4 forward gears, and an overdrive unit?

Correct?

If so, how many gears does the overdrive unit work in? All four? The top 2? Just top?

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You are really bad at picking up the point. I mean REALLY bad  :no:

Overdrive UNITS are normally only found on manual gearboxes.

BTW, BMW make what you would call a "small" car, e.g. the size of a Focus and the Saturn, and in the same sort of price range as other cars that size (which would in your terms make it a 'cheap' car, and not a luxury car). Guess what? Apart from the base 1.6 model which has a 5 speed box), all of them have SIX (yes, you read that right, 6!) forward gears. Even the autos!

So, just in case I am not understanding you, and before I lose all the will to live in trying to understand WTF you are on about...

You are saying that most American auto cars have 4 forward gears, and an overdrive unit?

Correct?

If so, how many gears does the overdrive unit work in? All four? The top 2? Just top?

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1. The BMW 1-series starts out at 16,000 pounds. That's $28,000 on this side of the pond. The Saturn I linked you to costs half that. Is the BMW 1 cheap? Sure, compared to other BMWs. Not to other brands. Meanwhile, I can go pick up a VW Polo for around 10,000 pounds, and guess what? You guessed it, 4-speed automatic. 10,000 pounds = $17,532

2. Yes, I am saying many of the sub-$20k (that's dollars, not pounds) have 4-speed auto transmissions. I can't say how all 4-speed auto transmissions work, but my parents own a Saturn (with a 4-speed auto trans), and overdrive only "kicks in" in 4th gear, not 1/2/3 if you select that.

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You are converting the UK price of a car directly into dollars?

Heh...

Doesn't work like that I am afraid.

$28000 is pretty much the US price of a brand new 325i in the US (USD$31000 compared to GBP?25500), if the 116i was ever sold in the US, it would probably come in well under $20k.

Anyway, if you look at cars that are sold in the same markets as the 1 series currently is, you'll see that it's priced pretty closely to the Golf / Focus / GM equivalents.

Anyways, thanks for confirming your parents car has an overdrive unit.

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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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should that be the other way around?

If you shift later you get higher RPMs, therefore more petrol is burned, shift earlier - less RPMS.

And if you shift sooner you lose acceleration or torque or whatever it is

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Anyways, thanks for confirming your parents car has an overdrive unit.

Lets get this straight. An Ion has a 4 speed automatic transmission. The fourth gear is overdrive. I'm not aware of any mainstream modern American car that has a separate overdrive "unit". I would also be surprised to find separate overdrive units in Europe or Japan in any large numbers.

I'm not trying to argue, just want the facts to be correct.

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this thread has way out of control :wacko:

All the thread topic was, what does the "S" Button do, and to put it in simple terms which have probably already been mentioned, it makes the car go into "sports" mode. Heck, even ferraris have this on their manual cars, and just gets the car ready for some serious thrasing :p

I dont know the technicalilty's but it gives you more acceleration for slight top speed sacrifice, and stiffens Suspension yada yada in cars that have the option..

Most of the time the car will just change the data in the ECU to enable the fuel injectors to work differently to give a richer engine noise and more acceleration.

I really dont know about this extra gear debate... :blink:

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Lets get this straight. An Ion has a 4 speed automatic transmission. The fourth gear is overdrive. I'm not aware of any mainstream modern American car that has a separate overdrive "unit". I would also be surprised to find separate overdrive units in Europe or Japan in any large numbers.

I'm not trying to argue, just want the facts to be correct.

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That's exactly what I was getting at. Anyway, the original question has been answered :D

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In short, usualy the "sports mode" on an automatic vehicle simply makes the automatic gearbox shift up higher in the revs, this is less fuel efficient but has better acceleration.

Some cars (vauxhall automatics tend to do this) also haeva cool feature, if you are driving in sports mode and you suddenly floor the accelerator, the gearbox will actually drop down a gear to accelerate faster.

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Some cars (vauxhall automatics tend to do this) also haeva cool feature, if you are driving in sports mode and you suddenly floor the accelerator, the gearbox will actually drop down a gear to accelerate faster.

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That has also been discussed, it's called kickdown. It's done using a switch that is pressed when the pedal goes the whole way down (e.g., past the normal full throttle position).

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Some cars (vauxhall automatics tend to do this) also haeva cool feature, if you are driving in sports mode and you suddenly floor the accelerator, the gearbox will actually drop down a gear to accelerate faster.

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I think all automatics do that... I know my 11 year old blazer does. It does it when the throttle position sensor goes above a certain point, although I'm sure there are other calculations involved, like how fast the engine is going.:D

Still wish it had a 5 spd manual though :crazy:

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