I just purchased an 07 1500 4x4 burb. Owner's manual states to not use chains on front tires! Why not? Maybe they meant specifically "chains" and not the newer cable chains, etc. I've already found ads for chains to fit the Burb with my tire size, p265x70rx17. Dunno. But, it doesn't make any sense to me to have 4x4 in snow and ice without putting traction device on front tires. Anyone got a clue?