DTC in snow?

[Bonds 25]

I have a 08 335xi. I was wondering if its better to have the DTC on while driving in snow. We got the first snow since I have owned the car last nite. I read the manual, but it dosnt really explain much about DTC.

[LeftcoastM3]

I keep mine on when I'm in the snow but sometimes turn it off if I get stuck.

I just got back from a 9 hour drive in the worst one day snow dumping I've seen in a long time and I left my traction control on just about the entire time.

We got sideways climbing a hill when I was forced to slow down and lost my momentum uphill. I turned off the traction control to get more power to straighten the car and then put it back on to control the wheel spin which helped me ease it up in 2nd until I was moving forward again.

I think it sorta depends on the situation but you might find that you'll keep it on about 98% of the time and only flip it off here and there.

[mryakan]

I keep mine on when I'm in the snow but sometimes turn it off if I get stuck.

I just got back from a 9 hour drive in the worst one day snow dumping I've seen in a long time and I left my traction control on just about the entire time.

We got sideways climbing a hill when I was forced to slow down and lost my momentum uphill. I turned off the traction control to get more power to straighten the car and then put it back on to control the wheel spin which helped me ease it up in 2nd until I was moving forward again.

I think it sorta depends on the situation but you might find that you'll keep it on about 98% of the time and only flip it off here and there.
Don't get him and every one else confused. DTC (which stands for DYNAMIC Traction Control) is turned ON when you hit the DTC button and turned off completely (alogn with all traction control and DSC) when you hold that button for few seconds. By default normal traction control is on (when DTC is off) and it intervenes faster than when DTC is engaged. Think DTC on = button pressed once = sporty traction control mode = more wheel spin = DTC sign on the instrument cluster. When all is off you get a triangle signal with a "!" in it.

Anyway, to the OP, I wouldn't drive with DTC ON unless you have to, the car can catch you off guard on icy roads. I usually only turn DTC on when I want to play (i.e. throttle induced drift on snow) or when trying to get unstuck or gain more momentum (e.g. in a parking lot with deep snow or up a snowy incline). Unless you are very experienced with snow driving (and even then), I would say don't turn DTC on unless necessary. I never turn the whole thing off unless I really want to play and that is only in an empty parking lot or somewhere safe. You got no electronic help then and things can get nasty real fast. As I always say, learning your cars abilities and limits in a safe environment is best before you start experimenting on the road.
Good Luck

[LeftcoastM3]

interesting...so what's the diff between DSC and DTC?

[sor]

Yep. Leave it all alone for very little slip(DSC), turn on DTC to allow more slip for a sportier feel, and hold the DTC button to turn off DTC/DSC completely and allow full slip.

Leftcoast, from what I get DSC is your classic electronic stability, DTC is the same thing only sportier, allowing more slip for aggressive driving and special circumstances.

[mryakan]

DSC = Dynamic Stability Control. It monitors the angle of the steering wheel and the direction the car is traveling in and if it senses that something is wrong (i.e. car going sideway such as when going too fast into a corner) it will intervene by applying the brakes to the appropriate wheels to tuck in the car and keep it in the intended line of travel. The physics are interesting, but you can experience the effects for yourself by leave DSC engage and going a bit too fast into a corner (safely off course). Safest way I tested it is to go into one of those merge intersection at a reasonable speed but one that you know is too fast for the car to go through without a bit of skidding, just let it cruise through and you'll see how you feel as if you are losing speed and the car will adjust as if on rails. Of course don't attempt this on busy streets or if you are not confident of your ability to take control if anything goes wrong and don't push it too much, even computers can't break the laws of physics.

Traction control (normal and in DTC mode) just limits slip to the rear wheel by applying the appropriate brakes if it senses one of then slipping, but with traction control alone a car can still understeer/oversteer into trouble if you overcook a corner, that's when DTC comes to the rescue (to a certain extent of course).

Drive safely.

[mryakan]

Yep. Leave it all alone for very little slip(DSC), turn on DTC to allow more slip for a sportier feel, and hold the DTC button to turn off DTC/DSC completely and allow full slip.

Leftcoast, from what I get DSC is your classic electronic stability, DTC is the same thing only sportier, allowing more slip for aggressive driving and special circumstances.
There is nothing classic about DSC ;). It was introduced not too long ago 1st on the 5-series then made its way to the 3. You are right about DTC though, sportier version of your default traction control.

[LeftcoastM3]

Sor and mryakan: Thanks for the info...very helpful :)

[mryakan]

Better BMW explanation of DTC/DSC here. Just look for DSC/DTC in the alphabetic listing:

http://bmw.ca/com/en/index_highend.html?prm_content=../../technology/tech_fs.asp?lang=en

[sor]

There is nothing classic about DSC ;). It was introduced not too long ago 1st on the 5-series then made its way to the 3. You are right about DTC though, sportier version of your default traction control.Sure it is, it's your classic ESP system that's been around since '95 on other brands. Classic meaning typical, not as in old as dirt.

[mryakan]

Sure it is, it's your classic ESP system that's been around since '95 on other brands. Classic meaning typical, not as in old as dirt.
Which brands are those? maybe luxury high end brands. Or maybe the last 13 years are blurring up for you (no offense intended, it does happen. I can't believe what the web was in 95 until I remember my days using gopher and original Mozilla 1.0 at the University). Anyway, in 95, barely any models (if any at all) even had traction control. I know that for a fact because when I bought my e36 in 97 that was the 1st model year that traction control was offered on cars in this segment and BMW had a big marketing hoopla around it (BMW 3 series on an ice rink and a catchy phrase like "we all need to get place" or something). Only a year or so later did traction control start to become common on other cars starting with high end and luxury models and then trickling to all others, and then only around 2000 or so did DSC or equivalent start to show up in mass production. Actually come to think of it, in 95 even ABS was mysteriously absent (at least as standard equipment and sometimes altogether) from many popular models.

P.S. The 1st occurrence of traction control at least in BMW lineup was on the 8-series (for those who remember it) during the early to mid 90s. That car was BMW's flagship and was full of gizmos too advanced for its time, but not many noticed.

[sor]

Sure, it's been optional on all Volvos since '95, when Mercedes (who was the first to offer it) licensed the MB-Bosch technology to them.

[mryakan]

Sure, it's been optional on all Volvos since '95, when Mercedes (who was the first to offer it) licensed the MB-Bosch technology to them.
Not very common/classic then, but let's not beat this to death. I got your point :).

[Takashi]

Thanks thanks :) hahaha I now understand what they are used for now.

Sometime in Oct a video explaining DTC and DSC means and their purpose was posed in the BMW USA website as "User Guides" for the Z4. For some strange reason this video is no longer available.

[MrOffshore]

As I always say, learning your cars abilities and limits in a safe environment is best before you start experimenting on the road.
Good Luck

This has always been my philosphy on driving...my father spent a lot of time with me in empty parking lots in snow and rain allowing me to safely learn what a car did in various situations...he wasn't enticing me to drive irresponsibly, rather he was teaching me lessons that could and may have saved my life. With cars you are rarely given a second chance...defensive driving is not the way to go through life...that's like waiting for something to happen...I drive offensively, always looking in front of me, beside me and behind me...looking to avoide the next possible problem...but if something does happen I think my fathers patience in truly teaching me to drive will pay off...I know when my children, including my daughters reach the driving age they will learn in the same manner...God keep them safe and hope they never need to use what they learned in a situation that may harm them or someone else.

[GrimmSpeed]

the last few days we've had alot of snow. in my experiece so far i've concluded that i like everything shut off the best(ie, hold button for a few seconds.) i've also concluded that i need to put the car away for the winter and bust out the winter car.

Justin

[Mad Dragon]

.

DTC Button
The DTC button is located in the center console between the central air vents and has
three operating modes:
1. DSC operational (standard setting)
2. DTC operational (If DTC button is depressed once DSC switches Off)
3. DSC and DTC completely deactivated (If DTC button is depressed for extended period

Dynamic Traction Control (DTC)
The functions of the DTC correspond to those of DSC with a slightly modified regulating
characteristics. DTC is activated by deactivating DSC (DTC button depressed). DTC
intervenes in the braking actions to imitate the function of a conventional differential lock.
Advantage: DTC allows better traction.
Vehicle stabilization intervention (e.g. reduced power output) is delayed slightly, compared
to DSC, which enhances traction with a slight loss of driving stability.
This function offers a compromise between driving stability and traction, especially when
accelerating and/or driving uphill on a loose surface or snow-covered road surface (surface
friction requiring more slip).
DSC provides a high degree of driving stability with adequate traction, however DTC
offers better traction with a slight reduction in stability. Therefore, the deactivation of
DSC should be reserved for emergencies (driving in deep snow, for example).

[Bonds 25]

Left everything alone, and suprise !! this damn car is pretty good in the snow. BTW thats with the sport's package 18 inch rim and tire upgrade. I have been driving in Buffalo lake effect snow for 15 years so i have a lot of experience, but even so I was very happy with the way the car performed. Im glad I bought the xi. Thanks for all the info

[Kernel Kurtz]

So enabling DTC disables DSC, as opposed to simply reprogramming it.......Seems they work on slightly different principles. I'm slowly starting to understand this.

I routinely enable DTC nowadays. I like the extra traction/wheelspinability and a the extra leeway it gives in a little bit of controlled sliding.

Would be nice if you could toggle between DSC or DTC as default.

[Qsilver7]

P.S. The 1st occurrence of traction control at least in BMW lineup was on the 8-series (for those who remember it) during the early to mid 90s. That car was BMW's flagship and was full of gizmos too advanced for its time, but not many noticed.

Ditto...I remember. :D BMW introduced ASC/ASC+T/DSC on the 1990 E32 & E31 Seven & Eight series (in various forms too varied to spell out which model got which technology). BMW has been installing "electronic" traction control systems for 17 years now. I had a 1991 735iL that had ASC...and my 1995 525iT has ASC+T. I believe ASC+T was available as an option on the 3 series starting in 1993.

You can see the ASC button (on top) and the EDC button (on bottom) on the small trianglar trim piece located on the left side of the center console below the HVAC control unit.

(1991 735iL)
http://memimage.cardomain.net/member_images/1/web/433000-433999/433594_158.jpg http://www.imagestation.com/picture/sraid40/pd54eb76360c63419e4e7da72ff8ec66f/fd028649.jpg

You can also see the ASC+T button on my 95 Touring in the pic below...same location (just below the HVAC control unit on the left side of center console.

(1995 525iT)
http://memimage.cardomain.net/member_images/1/web/433000-433999/433594_333.jpg

[tedmacwpg]

P.S. The 1st occurrence of traction control at least in BMW lineup was on the 8-series (for those who remember it) during the early to mid 90s. That car was BMW's flagship and was full of gizmos too advanced for its time, but not many noticed.

I'll never forget the Car & Driver August 1990 issue, which contained the first review I'd ever read regarding the 850 (with its DSC/DSC+T), etc... I can remember how impressed I was at the time. And so, a lifelong love affair with the brand was born... haha


So enabling DTC disables DSC, as opposed to simply reprogramming it.......Seems they work on slightly different principles. I'm slowly starting to understand this.


While that may be technically correct (I don't know), here's the way I think of it:

System in its default state (as when starting the car): No slip.
DTC: Little bit of slip. Enough to have fun on snow, within reason.
DSC Off: Lots of slip, no computer intervention.

[javamon]

RE: when traction control was brought to the masses, I had t/c on my grand am. in 1997. i'd define the moment it became widely available as the availability on GM's entry level cars. stability in GM wasn't available until 99/00, though, and only on the flagships of each division.

that said, the TC was very rudimentary. no electronic throttle, obviously, so it worked by retarding timing. it was actually very effective in small slip conditions (similar to racelogic's system), but when there was massive slip, it almost killed the engine.