Do you need 4 winter tires, or are 2 enough?

Four. It's the question we hear most from people trying to keep the cost down, and we understand why, but two winter tires is not half the safety of four. It can be worse than none, because it gives the car two different levels of grip and you don't find out which end lets go first until it does.

Two on the front: the back end slides out

This is the setup people usually ask about, because most cars are front-wheel drive and the front is where the power goes. With winter tires up front, the car pulls away and steers well. Then you brake going into a corner on ice, the weight shifts forward, and the rear tires, still on hard all-season rubber, have nothing left. The back of the car steps out and the car spins. It happens fast and it's very hard to catch.

Two on the back: the front won't turn

Put the pair on the rear instead and you get the opposite. The back stays planted, but the front tires can't grip enough to turn the car or stop it, so you turn the wheel and keep going straight. Safer than a spin, but still not where you want to be at a red light on a hill.

What about all-wheel drive?

All-wheel drive and four-wheel drive send power to every wheel, so the car gets moving from a stop in snow far better. That's all they do. Stopping and steering are down to the four patches of rubber touching the road, and an AWD SUV on all-seasons stops no shorter than a front-wheel-drive car on the same tires. Heavier vehicles can actually need more distance. The confidence AWD gives you pulling away is exactly why winter tires matter more on one, not less.

Matching matters too

Four winter tires is the rule. Four that match is the better version of it: same make and model on each axle at least, and tread depths close together. A worn tire on one corner pulls the car around under braking. If one tire is newer than the rest, it normally goes on the rear.

Not sure if last year's set has another season left in it? We cover how to tell in how long do winter tires last.

Cheaper ways to get to four

If cost is why you're asking, a full set of used winter tires is a better buy than two new ones. We check every used tire for tread depth, age and sidewall damage before it goes on a car; see used tires. Most insurers also want four winter tires on the car before they'll give you the winter discount, which helps pay for the set.

Once they're on, all four get balanced and torqued and the pressures set as part of the winter tire changeover.