My friend told me and he swear by his experience. This was an incident in which a car, not sure which drive, but was winter ready and it slid off the road and into pack snow. The owner could not get it to move back on to the road, no matter how he tried. He tried rocking back and forth. So my friend told him to let some air out of the driving tires and that did the trick. I have not tried this yet but is this practical. I don't think that vehicle that he was talking about was a 4WD. Any info. is appreciated.