For driving on snow-packed roads, I disagree about using 4wd only when absolutely needed.
The main reason is that on a snow packed road, 4wd lets you accelerate faster from a stop than 2wd. This is good if you have someone screaming up behind you who canâ€™t stop or someone who is sliding into the intersection you may be starting to cross.
Granted that the VDC, ABS and ABLS will get you around most of the time with no issues in 2wd, but if you have 4wd, why not use the extra capability?
Now, if you invest in a set of winter tires too, youâ€™ll have as good of a winter vehicle as you can get.
In a vehicle without VDC, particularly with a rear LSD or locker, 4wd greatly reduces the risk of acceleration induced over-steer. This situation becomes almost unavoidable as the road surface becomes icy or the grade of the road becomes steep enough that the power required to climb the grade overcomes the traction provided by the rear tires.
In my other 4wd vehicle, a fully locked CJ on MTRâ€™s, 2wd on snow and ice is essentially suicidal. Even just a little rear wheel slip causes the back of the Jeep to head downhill regardless of whether downhill is in up ahead or off to a side. 4wd reduces that tendency and helps to prevent rear wheel lockup under braking as well (the lockers and transfer case ensure all the wheels are moving at the same speed). Now, steering with the front locker on ice only happens when I get off the gas. Under power on ice, it essentially converts from hopeless oversteer in 2wd to nearly hopeless understeer in 4wd. Iâ€™ll take the understeering, thank you. I tend not to drive it too much in winter weather unless the snow becomes too deep for the X.