On snow covered roads with ice you can get by just fine without even engaging the 4WD. (carsdesk.com)
They reduce braking distance on cold, wet, ice and snow - covered roads in comparison to all - season tires. (cogginacura.com)
However, the car can also be driven safely on a snow - covered road with just front - wheel drive if the road is straight and speed remains constant. (greencarcongress.com)