I have a 99 AWD V8 Mountaineer with ltd slip rear differential. My testing ground is a 1/4 mile uphill washed out gravel driveway in Northern VT where the slope varies between 8 & 16%. Try walking up a snow and ice covered 16% slope and you may well be doing it on your hands and knees! In the winter 4WD and snows are a must. The only time I couldn’t make it up was attributed to Michelins with 80,000 on them. Cooper Discoverer Snows will get me up smoothly everytime, without the mad dash and thrash that most owners of 4WD’s insist is necessary to make it. The author’s theory of AWD may be true for some vehicles but certainly not mine. I have never been in a situation, ice or not where one wheel spins leaving the other three immobile and god knows I have tried! Another benefit to AWD that 4WD cannot boast, is even tire and tread wear without the necessary/constant need to rotate the tires. Any 4WD I owned was a guarantee to scalloped, uneven tire wear resulting in a loud rough ride and never getting much more than 40K out of a set of tires. I have 194K on my Mountaineer on the original snows and only the 2nd set of summer tires, I got 100K out of those original Michelins! I’ll take AWD over 4wd anyday!