[jimbethesda]

I sent an email to BMW asking this:

How does the new M Traction Control compare to MDM? For example, is MDM = M Traction Control level 5? Some other level? Does MDM work completely differently than M Traction Control?

I got this response:

"Thanks for contacting the BMW Genius Team.

The M traction control is a traction controller, which allows the customer in the rear-wheel drive to learn the oversteering in steps. For this, the M traction control uses the reverse control loop of the actuator wheel slip limitation. The customer can permit an automated defined slip at the rear wheels in 10 adjustable steps.

Unlike M Driving Mode, Dynamic Stability Control is off for M traction control. With M traction control, the customer has control of the wheel slip actuator. This means that with an optimally set slip controller the customer can concentrate on the necessary steering movements during the oversteer at the steering wheel without also having to control the drive torque at the same time.

For more technical information regarding these systems, I suggest speaking to your authorized BMW center. If necessary, I suggest speaking to the Service Manager. Should you need to access a list of our authorized BMW centers, please visit our website at: www.bmwusa.com, and select “Dealer Locator.”

I hope this information is helpful. Thanks again for your inquiry."

I'm still not sure I understand the difference in how it will react in the real world.

[m630]

It eliminates dsc so thats a big difference that would be felt in certain driving situations

[killhour]

Reads to me like they're different, non-comparable modes. Based on the description, M Traction Control seems to try to maintain a consistent level of slip at all times, while MDM is more like a safety net - hands off until it absolutely has to stop you from spinning.

In other words, M Traction Control is for when you want the car to do the work of maintaining proper throttle for a drift and MDM is for when you want to do it yourself, but still have the car save you if it thinks you're going to lose it. MTC probably won't do anything to stop you from binning it if you start to oversteer too much.