Every winter season I'm asked, "Do I need winter tires on my four-wheel drive vehicle?" Your four-wheel drive or all-wheel drive vehicle can indeed see a significant benefit by installing a set of winter / snow tires.
It's a common misconception that a four-wheel drive or all-wheel drive vehicle will not see much benefit from winter tires. This couldn't be further from the truth! The extra traction of four winter tires putting power to the ground is quite obvious in acceleration and cornering.
Most four-wheel drive owners don't have a problem with getting the vehicle going. An all-wheel drive vehicle equipped with good all-season tires can usually start moving without getting stuck. However, braking is another story.
A four-wheel drive vehicle with all-season tires can accelerate quicker than a two-wheel drive vehicle in slippery conditions. While this sounds like a good thing, it offers no advantage to braking and can create over confidence. In fact, most four-wheel drive vehicles are actually heavier and take longer to stop in slippery conditions than their two-wheel drive counterparts. A good set of dedicated snow tires make a big difference in braking during winter conditions.
As illustrated above, you can see how much of a difference winter / snow tires can make in braking, even if you have a 4WD SUV. It could be the difference between rear ending another car at an intersection (or worse).
I've owned a traditional four-wheel drive SUV (Toyota Land Cruiser) and went from Bridgestone's Dueler A/T REVO 2 all-terrain tires to Bridgestone Blizzak winter tires. Even though the all-terrain tires were quite good in snow, I can tell you from experience that there was quite a difference going to the Blizzaks, especially during braking.
On my Audi A4, an all-wheel drive sedan, I had the same experience when going from all-season Goodyear Eagle RS-A tires to the Bridgestone Blizzak WS series of tires. The same results applied on my crossover SUV, a Mazda CX-7, when I installed a set of Bridgestone Blizzak DM-V1. All three upgrades were on different types of four-wheel drive systems on very different vehicles and all showed the same result: winter / snow tires make a huge difference.
While shopping for winter tires, consider creating a Winter / Snow Tire & Wheel Package to make the changeover even easier!