I plan to 'winter' park my Z4 automatic in a garage that is down a fairly steep (but short) grassy slope. Going down should be no problem, and I plan to pick a dry day to come back up the the 40 foot slope.

I assume disabling DSC but leaving DTC on is the most effective traction coming up a grass slope at low speed? Also, if things get ugly I plan to tow the Z out using the front tow eye but the manual says the eye is only for towing on paved surfaces... any real risk towing on grass for about 20 feet?

Do you guys even have winter way down there?:stickoutt

If you leave the DTC on and your wheel starts to slip, you will go nowhere. It senses lost traction and reduces power/applies brake to the slipping wheel; then if the other wheel starts to slip it will stop also. The instructor at the BMW performance center said that slippery, uphill conditions are the only time you should turn off the DTC. Turning off the DSC will have no effect unless you are going sideways, which may happen if you go down a steep slippery slope into your garage.


GT

Do you guys even have winter way down there?:stickoutt

No, we don't. :D

Try starting in second gear instead of first. This is an old winter trick. It puts less torque to the rear tires so less chance of spinning them. You can do this with either the automatic or, of course, the manual transmissions.

If you leave the DTC on and your wheel starts to slip, you will go nowhere. It senses lost traction and reduces power/applies brake to the slipping wheel; then if the other wheel starts to slip it will stop also. The instructor at the BMW performance center said that slippery, uphill conditions are the only time you should turn off the DTC. Turning off the DSC will have no effect unless you are going sideways, which may happen if you go down a steep slippery slope into your garage.


GT
yeah I learned this the hard way. I blocked center city traffic for 2 cycles of lights while battling the traction control with 1" deep snow