SugarRushMurano,
I think what you said is true, but I don't look at it that way. AWD or 4X4 to me is not a safety device in slippery conditions, VDC is. Now you can use AWD to pull you through a turn faster (shorter turn radius), but AWD in of itself just helps you get more traction. For example going up a slippery hill. What putting power to both axles does is increases your drive contact patch surface area (drive wheel friction).
Again, neither of these two help you stop any faster. ABS/EBD does but we're not talking about that right now.
Likewise, I have driven 2WDs and 4WDs for years in various places I have traveled to and lived in and have never had an accident. A 4WD memory comes to mind. I was driving down the interstate in moderate snow (6-8") with my Cherokee in the left lane where a lot of cars and SUVs were running in the right lane. The right lane had deep ruts and the left lane was virgin snow covered. As I looked in my rear view mirror I saw 2WD cars and 4WD SUVs try to pull into the left lane (where I had just cut a path in) and they ended up spinning out in the median. A 2WD memory comes to mind, when I lived in Ohio I was driving a 1965 Pontiac Catalina with snow tires and concrete blocks in the trunk. The roads were iced over and everything was closed but I had to get to my grandmas because she had a water leak. Nobody was on the road, not even the salt trucks. My secret, I put the right two tires in the berm and gently applied brakes to get traction and went slow.
My point is, there is a lot to know about both 2WD and 4WD and how to use them in various conditions. What we think is "common sense" often isn't and sometimes is anti-intuitive. I have some offroading and 4WD experience so I know some things, but not everything. There is always more to learn. The best thing to do is find an empty parking lot and teach yourself as previously mentioned. There is also a lot to learn about the capabilities and limits of any given vehicle. While there are some similarities between my MO and Jeep, there a lot of differences.
Also, you don't need AWD or VDC or even ABS or EBD. But each one of these marvels of engineering adds a different capability and complement each other well. But none of them will overcome lack of experience or ignorance. Ignorance is defined as absence of knowledge. We are all ignorant until we learn.
A few things that come to mind:
In all cases, go slow and plan ahead, your stopping distance on slippery conditions is much much greater. Give yourself room. Also, when moving, energy is defined by onehalf times mass times velocity squared. In other words, it takes an increased proportionate/linear amount of more energy to accelerate or stop the heavier the vehicle is, but increasing speed increases energy by the square. Say mass is 1 and velocity is 1, energy is .5. Say mass is 10 and velocity is 1, energy is 5. Say mass is 1 and velocity is 10, energy is 50! Velocity is drastically more important than mass.
Traction is basically friction. Anything you can do to increase the friction between your tires and the road is good.
Stay out of ruts, always try to cut your own path. I love a freshly snow covered road that no one has been on. If ruts are present, ride in the fresh snow lane or if one lane, ride on top of the hills not down in the valleys. Even if the rut is only a half inch deep. Cut your own path, don't follow in someone elses. If you can't get both sides on top at least get one side on top. Remember you only have so much clearance under your vehicle, you don't want to hang up the chassis (high center) or drag it.
Let some air out of your tires to flatten out the tread blocks, this increases the surface area contact patch and increases tread flex to kick out snow that builds up in the treads. But put air back in once the roads clear or they become discontinuous (wet/dry).
If in an emergency, put the right side of your vehicle on the berm, but know the road well so you know there are no concrete curbs, steep drop offs etc and realize that you could end up with a flat.
If there is a small particularly slippery spot (hard packed snow or ice) or you are stuck (make sure your chassis isn't hung up, dig it out if it is), put sand, dirt tree branches or something in front of the tires and over the slippery spot.
Don't spin your tires. I don't know how many times I see somebody gunning their engines with their tires rotating a hundred miles an hour and the car is just sitting there or creeping. Apply slight power and gently tap your brakes to act as a temporary limited slip differential. This will engage the other drive wheel(s) on the axle(s) and double your friction. Again, friction is the key. Static friction (before slip) is greater than dynamic friction (after slip). If that doesn't work, try some of the other previously mentioned ideas. If none of these work, you need better tires, chains, studs or a plow.
Discontinuous drive path - dry spots. Try to avoid these, either stay on all dry or all snow. Sometimes you can't, sometimes there is a dry spot or slippery spot all the way across the road. What will happen is the wheels will grab and slip. Try to go through these such that the wheels are perpendicular to the discontinuity. Try not to take them at an angle or in a turn.
Discontinuous drive path - ruts. Be careful not to high center when crossing over the high spots of ruts. Avoid hanging or dragging the chassis. Try to cross these at a very slight angle, first ease your one sides front wheel up on the high spot of the rut (mountain) then ease that sides rear wheel up. If the distance from the mountain to the valley exceeds your chassis clearance, don't go over the other side such that you straddle the mountain. You want to straddle the valley. If you have to cross ruts, drive a little further and plan ahead where you won't run the risk of high centering or dragging the chassis, where the rut isn't so deep. If the rut is across the road and you have no choice, make sure you have chassis clearance and creep over it, if you don't have clearance (mountain is too high), get out the shovel and level the rut. The key is, watch your chassis clearance.
Chunks of packed snow or ice (snow boulders). Try not to drive over these (under chassis). It is better to hit them on the inside edge with your tire then to hit them with something under your chassis. When you hit them with your tire, either it will break apart and or get pushed out of the way. But make sure you hit it one the inside edge such that if it pushes, it doesn't push under the chassis but out away to the median or ditch.
