So, my wife & I experienced our first snowfall in the new G37x AWD 4dr sedan. Overall, the car handles well but it has a strange (and somewhat dangerous) quirk. Separately, we both experienced the rear end sliding out while at a standstill in traffic on snow covered roads. I figured out it happens when I let off the brake a little while in "Drive." I have surmised the rear wheels must be turning but the fronts are still locked, causing the rear end to shift to the side as the rear wheels are trying to push the car. Having never driven rear-wheel drive cars in the snow (79 VW Fastback aside), so I don't know if this is typical. The car seems to do this with the "SNOW" button depressed or not. Putting it in neutral stops the side slipping immediately. I figure the rear brakes must be getting over come by the drive force of the tranny and engine while the front wheels are still locked.

According to the manual, the "SNOW" button is supposed to create 50/50 torque split (front to rear)... Assuming this takes power from the rear wheels (which typically start with 80% available power, I understand) works against my theory. Yet, it "feels" correct and "tests" correct (as Neutral stops the side-slip, as does more brake pedal pressure), but I haven't ever been able to stand outside the car to observe this phenomenon while it's happening. Has anyone else experienced this rear-wheel side-slip in either this car or other RWD cars? The dangerous thing is that on crowned road surfaces with narrow shoulders, one could easily find the rear end in the ditch and become high-centered if you let the car continue slipping (and it happens pretty quick, i.e. 6-12 inches of side-slip per second, appx.). The car seems it would continue to side-slip to at least a 25-30 degree angle if I'd let it.

Any opinions, explanations, coping techniques? I've driven in moderate snow all my life, but my wife hasn't and this quirk freaked her out initially. I doubt I can do anything to remedy this, but wanted some confirmation on my theory or other explanation. I wonder what snow tire would do to this characteristic?

 

Sounds to me like your just not getting traction so when you start to go the rear just starts to slide out.

Are you one stock tires?