Z4 handling on wet roads
Z4 handling on wet roads.
In the rain, it feels like I'm loosing traction on all four wheels at speeds above 75 km/hr (45 mph). It only happens on uneven paved surfaces that have a slippery finish however I am surprised that it's happening at all. My tires are slightly worn but I think it might be something else about the Z4 that causes this. Has any one else experienced it? What are the causes?
The long version:
I bought a 2011 Z4 30i 2 months ago. Yesterday, I was driving on the highway at about 80 km/hr (50 mph) and the front wheels hydroplaned for a brief moment. It was quick enough that the car self corrected and there was no loss of control. The pavement was flat and there was a moderate amount of water building up on the road but nothing exceptional.
A few kilometers later at about 70 km/hr, it felt like all four wheels were hydroplaning for brief moments as I drove down the road. The movement was subtle but it was definitely the beginning of a situation where you might lose control. I slowed down to 60 km/hr and just took it easy the rest of the way home.
Today, it was raining again so I drove around trying to get the car to repeat what happened yesterday. The car felt solid on any of the wet surfaces I tried.
I did however drive on an uneven two lane road with pavement that looked slippery. Driving straight at 75 km/hr, I can feel the entire car start to come loose. All four wheels seem to lose grip and it's like the entire car starts floating a bit. I was in disbelief because I was going so slow. I drove this road up and down several times trying to understand what was happening and it was the same behavior every time. At any speed lower than 60 km/hr, the car is fine. Anything above that and it's like you're on ice.
It's not the dynamic stability control (DSC) because the car did the exact same thing when I shut it off (push and hold the traction control button for about 5 seconds and you'll see DSC off on the display), although the car seemed to do it less when it was off.
The tires are the original and the tread is low especially in the back but not bad enough that I would have predicted that I would lose grip in the rain at these speeds. I'll attach photos.
I should mention that the temperature is a little low, around 10 degrees C or 50 F. I checked the pressure in my tires two weeks ago and added air to the recommended pressure (38 PSI front/44 rear, or something high like that).
Has anyone ever experienced this? Is this normal and what is the reason for it (tight suspension, wide tires)?
Last edited by BChmiel; 06-01-2015 at 03:31 AM.