I was watching a TV ad about a 4WD SUV, the announcer was talking about driving on “Black Ice”, and he mentioned that if you press the correct buttons or switches on his vehicle, you solve the problem. PURE BS – “Black Ice is a phrase used to define a road covered with ice – unless this SUV can alter the laws of physics –driving on black ice is dangerous and a challenge.
No matter what the TV ads show no 4WD system will make up for a decrease in adhesion. When ice – snow – etc creates less adhesion between the tire and the road, the vehicles capability to go – stop – and turn is greatly diminished.
The problem is that most 4WD/AWD drivers think they have a vehicle that can defy the laws of physics. Stopping on snow and ice will require up to 10 times the distance as stopping in normal conditions, and driving onto an off ramp during a black ice or wintry conditions will require a lot less speed than usual, and the driver will have to anticipate that lower speed way before they get to the off ramp.
When driving in bad weather the best advice is slow down.