smckenna

I've got a two-part question:
First, what is the fundamental difference between putting the ECT Switch in "PWR" mode to select a higher shift RPM in the transmission, and putting the gearshift **** in the S-mode? Keep in mind that I don't care about shifting the car myself by bumping the gearshift know forward or back (not my thing). In all the previous BMW's that I've owned, just by putting the gearshift **** in "S" (sport) mode, it was more aggresive, and I could actually tell the difference (even in the suspension handling).
The second part of my question is simply, what exactly does the gearshift know "S" mode do? I see a very confusing chart on page 153 of the manual, and have no idea whatsoever what it is trying to convey to me:
Shift Range Function
----------- ---------------------------------------------------------
8 Automatically selecting gears between 1 and 8
according to vehicle speed and driving conditions

7 Automatically selecting gears between 1 and 7
according to vehicle speed and driving conditions

6 Automatically selecting gears between 1 and 6
according to vehicle speed and driving conditions

5 Automatically selecting gears between 1 and 5
according to vehicle speed and driving conditions

4 Automatically selecting gears between 1 and 4
according to vehicle speed and driving conditions

3 Automatically selecting gears between 1 and 3
according to vehicle speed and driving conditions

2 Automatically selecting gears between 1 and 2
according to vehicle speed and driving conditions

1 Setting the gear at 1
"A lower shift range will provide greater engine braking forces
than a higher shift range"

Could the entire purpose of this thing be for when I am returning from a trip in the North Carolina mountains and I am trying to use the engine to slow my decent down the mountain so I won't burn out my brakes? Is that the entire picture here? Or is there also some performance / sport for using this, other than for those people who just like to manually shift the transmission?
Thanks in advance!
=Steve=

spwolf

you are selecting maximum gear for the vehicle - for towing, engine braking, etc, etc. Some people feel it is sporty as well as the engine will not upshift when in manual mode.

PWR mode will keep the engine in higher rpms and make car react faster to your inputs.

rominl

iTrader: (4)

it could be a 2 page explanation, but in a nutshell

1) putting the ect in pwr would tell the ecu to be a bit more aggressive on rpm before shifting, and also depending on your throttle, the car might downshift earlier than normal to get more power, etc...

2) putting the car in s pretty much tells the car what is the HIGHEST number of gear it can be in. make no mistake, it is not tell the car EXACTLY what gear to be in.

for example, when you are on local at 40mph, put it in S, it says 4. that means the car will keep 4th gear as the highest gear it will in. so that means if you come to a complete stop at the light and then start the car again, it WILL start in 1st gear still. then 2nd, then 3rd, then 4th. however, it will hold at 4. so if you then get on freeway and "forgot" to "push the shifter" to 5 or above, the car will keep on reving up on 4th gear to 60mph, 70mph, etc...

another example. you are on freeway doing 80mph, the car is in 8th gear. you put it in S, you see 6 (the car will automatically shift it down to 6th). that means the car is now in 6th gear. you have more power coz' of the lower gear, so you have more passing power. but say then you hit traffic and bumper to bumper, the car will shift down for you, down to 1st if needed.

now the difference? putting the car in S does NOT change the shift point if the car shifts itself (for example in S4 but when you go from stop, going through 1-2-3-4). putting the ect in pwr changes the shift point.

reading your post that you are not the kind of person to push the shifter forward and backward? i say just keep it in the pwr to get the little bit of extra aggressiveness from the tranny / engine. it might not be very noticeable, but that seems to suit you more

Mike_TX

Or to put it in simple terms, using the "PWR" button does the same thing putting your BMW in "S" mode did (except for suspension changes). That is, it makes the transmission and accelerator more responsive.

Putting the shift lever in "S" mode on the LS460 merely limits the transmission upshifts to the gear displayed. Now, if you were in the mood to "bump" the shift lever, you could also use "S" mode to downshift and upshift manually. That's sometimes handy for the situations you mentioned - i.e., going up and down steep mountain roads and that sort of thing, where you want to decide which gear you want to be in.

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smckenna

Thanks to all 3 of you for responding. This has been very informative. To avoid "forgetting" that I have put it into S mode while going 40 MPH (S4), and possibly blowing up my enginge as I get out onto the freeway, I think I'll just leave that S-mode alone and stick with my ECT button on PWR for my agressive driving.
Thanks again!

dmvp29

Would driving in S4 mode going ~60 MPH on the freeway really cause excessive stress on the engine?

rominl

iTrader: (4)

yup, in your case, just keep it in pwr is fine

s4 at 60mph shouldn't be too bad, don't know the exact rpm but i don't think it will be very high. if you accidentally put it in s2 and going 60mph, then it's definitely putting a lot of stress on engine and tranny (but i guess you should know by then coz' the engine is reving pretty high)

allklr

iTrader: (1)

I have been messing around abit doing some burnouts....is there some kind of cutoff that keeps you from going over the redline?

rominl

iTrader: (4)

of course, at redline there is always a rev limiter, otherwise you can blow the engine

Mike_TX

(Memo to self: Don't buy allklr's used LS.)

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gserep1

I wouldn't want that car either.

allklr

iTrader: (1)

Burnouts wont hurt anything.....Especially since there is a rev limiter.

Mike_TX

We're just kinda pulling your chain ... kinda.

I figure the forces necessary to overcome the weight of the car and spin the wheels on a dry surface are sufficient to put stress on the transmission and other drivetrain components. They should be up to it, but it's still unnecessary stress IMO.

But it IS your car ...

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rominl

iTrader: (4)

i am not sure if i agree with that. it's still a way to abuse the car

allklr

iTrader: (1)

I'm not brake torquing or anything like that, with the Chicago cold weather and icy streets it pretty easy to get some wheel spin going with the traction control off. I just noticed that the rpms shoot pretty close to redline sometimes. Maybe I need to get that E63 that I have been checking out.....