I recently bought a 2015 Countryman S All4 and park it in a steep driveway (only shady spot) at home. Think San Francisco, but a little less steep. The car faces downhill, and I need to reverse uphill in order to back out of the driveway. I've noticed, however, that when I release the parking brake and step on the gas to go in REVERSE, the rear of the car will "lift" a little before continuing uphill. This happens every time.

Is this normal? It's a little jarring, and I'd like to know if I'm damaging the car in any way by having it parked like that and going straight to reverse all whilst going uphill. What's going on?

 

Probably a question for a physics forum, torque, loads, etc.

 

I am wondering if it has anything to do with the hydraulic clutch system and whether the oil is running back to the front that is lower.

 

If it is a manual transmission, this could be the hill hold feature holding the car from moving. If possible, Try waiting a second or two after you release the parking brake.

 

Its pure Physics, the CM is FWD unless they spin so when you back up the weight is all in the front caused the rear to lift a bit. Think of a Fulcrum with the theoretical center of the car being the pivot point.

 

In my feeble head I can picture the front tire turning clockwise to make the car go backwards. As the front end is already lower than the back, I am trying to figure out why the back of the car would want to lift up. As the front of the car is already the most heavy, and with it already facing down hill, I am thinking that you would need an amazing amount of force to make the back end lift up.

I would think that if the wheel force was due from the car going forward that the tire turning counter-clockwise would create a negative affect on the rear end making it lighter.

But then I am never going to have to worry about somebody stealing my brain when I die.

Hopefully we have some physics folks here.

 

I think it is the hill hold feature. It will hold until you apply gas I think, so it acts just like the opposite scenario on any regular driveway.

Say you drive up a steep driveway and only apply the e-brake to hold it (car in N).

Gravity will pull it backwards (like you are doing with the gas) and the rear will lift since the rear brake is applied.


I had this problem parking 'normally' in a driveway with my manual R56...rear would rise up while parked. I noticed, because all my pictures looked stupid and ***-high parked in my driveway. No problems on flat ground.
If I parked face-down and applied the e-brake (because manual), it would look badass because the parking brake would actually pull the back of the car down and make it a little lower!

 

I went and tested this morning. Stopped on a steep hill and applied the e-brake and let the car move forward in neutral. The rear squatted down on the e-brake. Then I released the e-brake and immediately went into reverse. The hill hold kept the car in place and the rear raised way up before starting to move. I then tried the same but waited a second before reversing and the rear only raised a bit.