Well, got the woman's 96 Explorer (4.0) in good running order now. Changed oil with some Maxlife 5w30, 1qt of MMO, and a Fram Tough Guard filter. Replaced the fuel filter...what a pain. It should have been easy, but even with the tool to release the couplings, it the lines didn't wanna let go. Also replaced the PCV valve and fixed a coolant leak. If the old PCV valve is any idication, the inside of her engine should be pretty clean, but we'll see if the MMO does anything for it. Also changed the belt. That was scary, I was looking for the tensioner, and when I found it, it was all kinds of katywampus. Thing was ready to fly apart, I can't believe it was keeping any kind of tension on th belt. The amazing part is the belt only squealed a little bit first thing in the mornings, after that it didnt' make a sound. Replaced that and now she should be good for another 5,000. After this fill, I might give Mobil 1's HighMileage stuff a try. I was trying to avoid going with synthetic in hers to cut down on costs, but shes the type to start it up and take off before it even builds oil pressure, and she does a lot of idling and short runs, so this oil might be a better choice for her.