co64

My wife stepped up from an all wheel drive Mazda CX-9 to a GL550 a few days ago. One odd difference that we weren't expecting was how the two felt drive in the rain through large pools of water on the side of the highway. I compared both back to back (within 5 min). In the Mazda, you may feel the car pull slightly towards the (right) side of the road with water, but usually nothing dramatic. In the GL, there's an odd feeling of pulling towards the water (even a bit more than the Mazda), but then it pulls in the opposite direction (back to the left) I think. It happens so fast, it's hard to make out. It almost feels like the GL is compensating for the loss of traction on the right wheels. What exactly is going on? It honestly feels less stable than the Mazda in those micro-instances, but I guess it may be getting used to some electronic compensations. Thoughts?

cookstar

I would say that you might be losing traction in one or more wheels thus the torque is sent to the wheels that have more/higher grip, how fast were you going? hard to lose grip in rain with 10 inch tires though, even in our old GL with the 8.5 inch tires we never felt had any problems like you describe.

fabbrisd1

Yes - part different chassis and different footprint - also better to get well seated with the fact electronic compensation - ETS - is a very good thing (except for "dirfters").

Informative Mercedes ETS video which might help you and your wife rest easier:

co64

Was driving approx 60 mph.

Thanks for the explanations and for the video link. Very informative. That does seem to describe what we felt.