When it snows many drivers let air out of their tires assuming they’ll get better traction. Don’t do it because with modern tires this will usually lead to less, not more traction. You may also feel that adding weight over the rear wheels will increase traction. This one is true however never use solid items such as concrete blocks, bricks, or heavy pieces of metal. Even a minor fender bender or bumping a curb could cause heavy, solid items to come crashing through the rear seat leading to severe injuries. If you’re going to add weight it should be sand in soft bags placed low in the trunk. The bags that contain the sand must be light enough that during a crash they break open rather than permit the weight of the sand to propel them into the passenger compartment.
