Some model years have an opening on the side of the hinge for greasing. If yours has a small round hole on the side of the hinge, you can put a needle attachement on your grease gun, press the needle hard into that opening and inject grease into the hinge. I've had some hinges not take grease, hardened I suppose. I've also had good results with lithium grease in a spray can. The grease is dissolved in a carrier solvent which evaporates leaving the grease behind. This penetrates fairly well into a hinge. The spray is useful for lubing mechanisms inside the door, hood latches, etc. Can be a little messy though.