Went to Pep Boys to buy some stuff including a tube of chassis grease. Looked on the shelf to grab some synthetic Mobil 1 grease as I usually do and thought "Is synthetic grease really necessary for lubing the ball joints\steering linking ($6.00 plus per tube)? Was just about to grab a tube of regular $1.99 chassis grease but decided not to buy any for now. So what do you think, is synthetic grease necessary?