Hello - I am new to this forum, but have been reading for some time. Just wondering what would be a good oil for my 1995 Jeep Grand Cherokee. It's a 5.2L 318 with 164,000 miles. Seems to be running great still – bought it from a friend of mine a few months ago just to mash around with in the winter. God knows what has been used in this thing in the past....it's got Quaker State 10w30 dino oil in it right now with Quaker State filter. It doesn't smoke, burn oil, leak, and gets 17mpg in mixed driving still. Idles smooth and quiet still, so I think it has a little bit of life left in it. What would be a good oil for this thing to ensure that it keeps on rolling? I was going to use either Mobil 1 High-Mileage 10w30 Synthetic or Valvoline Max Life 10w30 in the maroon bottle, just to clean this thing up a little and make sure the gaskets keep things sealed up for the time being. Is this over kill and a waste of money, or am I better off just sticking to regular oil?