S-Class (W220) 1999-2006: S 320 CDI, S 320, S430, S 500, S 600

Tiptonic gear shifting

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Old 08-08-2012, 02:50 AM
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'01 W220 S320 CDI, '96 W210 E220 Diesel, '94 W124 E200, '89 W124 E250
Tiptonic gear shifting

Hello guys.

I prefer to use the tiptronic function in my W220 as I could use engine breaking to slow down my car and reduce wear on my brake rotors. I just want to ask if it is ok to shift down in a hurry? Suppose you are cruising in the 4th gear and you see a car crossing an intersection just ahead, so you want to slow down the car to the 1st or the 2nd gear in less than 2 seconds. Would this kind of shifting cause any undue strain or damage to the automatic gearbox?
Old 08-08-2012, 04:59 AM
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2003 S500, 03 C240, 03 E320, 03 tahoe
no "pun" intended

stop that!. automatic transmissions are designed to move you forward, smoothly and efficently. brakes are a wear item that "sacrafice" themselves at an affordable replacement cost. they are specifically designed to slow you down for any reason you choose.
Old 08-08-2012, 07:37 AM
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UNLESS you are raod racing, or autocrossing, USE THE BRAKES!!!

And those two situations are HIGHLY unlikely in a W220

Unless you are like me
Old 08-08-2012, 09:06 AM
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Originally Posted by forever_benz
Hello guys.

I prefer to use the tiptronic function in my W220 as I could use engine breaking to slow down my car and reduce wear on my brake rotors. I just want to ask if it is ok to shift down in a hurry? Suppose you are cruising in the 4th gear and you see a car crossing an intersection just ahead, so you want to slow down the car to the 1st or the 2nd gear in less than 2 seconds. Would this kind of shifting cause any undue strain or damage to the automatic gearbox?
absolutely terrible logic.

You want to save wear on $300 brake rotors by aggressively shifting a $7,000 transmission?

simply stop doing this.
Old 08-10-2012, 12:35 AM
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I suppose it's possible, but I see two problems:

1. The speed of the shift: S-Classes unless you reset the TCU will provide "softer shifts", meaning that longer gap or slower shift between gear engagements might give lateral forces similar to downshifting too early (this is usually eliminated in automatic cars that "blip" the throttle or double-clutching in a stick shift car).

2. Shifting down in a "hurry": To protect the transmission, often the Mercedes TCU will prevent the driver from actually downshifting until the speed and RPM is low enough for the next lower gear. For example, if the TCU judges that 5500RPM is too high for the next gear it will downshift to, the car needs to slow enough that the next gear's RPM is low enough.

Oliverk finds that this idea is too aggressive; from what I know, Mercedes TCU programming prevents a significant amount of ways to destroy the transmission, such as automatically upshifting at the rev limiter and what I mentioned in point #2.

In my opinion, this is not necessary unless you are going down an extended descent such as driving down Mount Washington Auto Road from the summit.

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